Cobra or catastrophic insurance

I’m about to leave a job and go on a long bikepacking trip. At the end of the trip I will be going to grad school and getting student health insurance. This is all in the United States. I have decent savings so I could cover pretty much any fee but I’d rather not. My understanding is that if something happened I could retroactively sign up for cobra for a 90 day period though it would be expensive. Alternatively I can get catastrophic health insurance to cover anything that might happen. The way I see it I can avoid paying any premiums if I take the cobra option but it may be costly to activate it if anything happens. If I get the catastrophic coverage I will have to pay some premiums but will be covered in a worse case scenario.

I am an otherwise young healthy individual who requires no regular medication or treatment.

Are there other things I should consider?