Commas with multiple prepositional (adverbial) phrases at the end of the sentence on the ground of restrictive/non-restrictive modifier

Do we put commas between 2 or more prepositional phrases that immediately follow each other at the end of the main clause if all of them modify/restrict the main predicate differently (e.g. one defines when; the other defines where; the third defines time or circumstances, so all acting restrictively)?

Examples below (please don’t suggest the word order change; I am trying to understand the restrictive/non-restrictive logic with these):

1. He died in 1989 in a car accident in Detroit. ("in 1989" defines when; "in a car accident" defines circumstances; "in Detroit" defines where – 3 prepositional phrases restrict the main predicate differently; hence no commas between the 3 phrases?)
2. He died in 1989 at his home, in Detroit. ("in 1989" defines when; "at his home" defines where; "in Detroit" also defines where – prepositional phrases 1 and 2 restrict the main predicate differently; hence no commas between these & prepositional phrases 2 and 3 restrict the main predicate in the same way; hence the 3rd phrase becomes non-restrictive, modifies "at his home", and requires commas?)
3. Tom gave a good speech on Monday at the marketing conference. ("on Monday" defines when; "at the marketing conference" defines where – the 2 prepositional phrases restrict the main predicate differently – hence no commas between the 2 phrases?)
4. Tom gave a good speech on Monday at the marketing conference at 5.30 pm. ("on Monday" defines when; "at the marketing conference" defines where; "at 5.30 pm" further narrows down yesterday to the exact time – 3 prepositional phrases restrict the main predicate differently; hence no commas between the 3 phrases?)
5. I lived in London with my girlfriend between 2001 and 2006 ("in London" defines where; "with my girlfriend" defines circumstances / with who; "between 2001 and 2006" defines when – 3 prepositional phrases restrict the main predicate differently; hence no commas between the 3 phrases?

Up until recently, I thought the punctuation and logic above was correct, but having read, The Writer’s Digest Grammar Desk Reference on non-restrictive prepositional phrases, I am now in doubt.

According to The Writer’s Digest Grammar Desk Reference:

In the sentence She lived in San Francisco until her death in 2002, for example, the prepositional phrase in 2002 is functioning restrictively. It is distinguishing the woman’s death in 2002 from her death in some other year. In other words, the sentence is implying that the woman died more than once. Surely, however, that is not the writer’s intended meaning. The prepositional phrase in 2002 is in fact providing only supplementary information, not essential information. Inserting a comma before the prepositional phrase will resolve the problem.

Using this logic, I would then be inclined to say that my sentences (5), (1) and (3) above should also be changed to say:

• (5) I lived in London, with my girlfriend, between 2001 and 2006. (Commas
  inserted, as no commas imply that I lived in London multiple times –
  one happens to be "with my girlfriend"; and I lived with my
  girlfriend in London multiple times – one happens to be "between 2001
  and 2006".)

• (1) He died in 1989, in a car accident, in Detroit. (Commas inserted, as no commas imply that he died multiple times in 1989 – one happens to be "in a car accident"; and he died in multiple car accidents – one happens to be "in Detroit".)

• (3) Tom gave a good speech on Monday, at the marketing conference. (Comma inserted, as no comma implies multiple speeches on Monday, one of which happens to be good and be at the marketing conference.)

To me this rationale makes sense only if the second prepositional phrases modify/restrict the combined predicate + first prepositional – e.g. in sentence (3), "at the marketing conference" modifies/restricts combined phrase "gave a good speech on Monday" to specific location; "on Monday" in turn modifies/restricts "gave a good speech". In this case, I would say commas are correct (only if "at the conference restricts "speech on Monday").

But, if both phrases "at the marketing conference" and "on Monday" independently restrict/define "gave a good speech" differently (one defines where; the other when), then surely there should be no comma here (on the grounds that both phrases independently define important info about the predicate and answer different questions – one where; one when – so no comma is required between 2 different independent modifiers)? (Same rationale for sentence 1 and 5: if phrases modify each other, commas; if all modify predicate, no commas.)

University of Illinois seems to agree with my rationale and support no comma theory below:

Two or More Phrases

When two or more prepositional phrases follow each
other, they may modify the same word, or one phrase may modify the
object in the preceding phrase:

They arrived at the airport on time. (Both phrases modify "arrived";
"at the airport" tells where and "on time" tells when.)

To me the example below would qualify for The Writer’s Digest Grammar Desk Reference comma rationale:

We were good friends until he died, in 1989, in car crash, in Detroit. (Here "until he died" is the main point; rest is non-essential. But this does not seem to be true for above sentences, where these phrases are essential information.)

On these grounds one might lock themselves into thinking that aside from the core clause all modifiers are not restrictive:
If "she died in London in 1990", "in 1990" in non-restrictive, one can argue that so is "in London" and the basic meaning of the sentence should be "she died". Otherwise, why is the first modifier essential and second is not if the tell 2 different things about the predicate "died": one saying "where" – in London; the other saying "when" – in 1990. Both define "died" and do not restrict each other, but rather provide essential info about the predicate?

So what is the correct punctuation and rationale? Are these phrases restrictive or not and what determines that?