How to transition away from dog walker?

Background

So currently we have a puppy that is approaching 6 months of age and is a Miniature Golden Doodle. Both my wife and myself work jobs where we will be both be gone for about 8 hours a day so we have had a dog walker come half way during the day to let our puppy out for half an hour.

Currently she does wonderfully in terms of potty training. She has never had an accident in her crate and hasn’t had an accident in the house in a long time.

Problem

So obviously a dog walker costs money so what is a good way to transition away from a dog walker and at what age? (i.e. do task A when puppy is 6 months old, task B when puppy is 8 months old, etc.) We definitely don’t want to ruin our success with potty training at all or create any separation anxiety if she has to be alone for a long time such as 8 hours. Any suggestions are welcome!