I've got a 2nd floor detached garage build i'm in the planning/permitting stages of here and looking for advice to see if any key features need added.It will have its separate entrance from main garage which will be utilized by main house STR for a game room eventually.

Hi I am living in grand forks North Dakota.

Construction materials: Frame, no basement, roof: asphalt shingles, Floor: Carpet on stairs and bedrooms, LVP: Kitchen and living room.

Got a 2 bed 1 bath property in California that has a AC unit in the living room and a wall heater (older home).

I need it just often enough to send or receive items from vendors or local govt's to want the convenience of using it from my home, hotel room, or office.  

If you can still make payments then they are happy.If you travel for work, you can still rent out a portion of your residence (rent by room) and rent other unit.

Not something I typically get involved with so was curious as to what rent/room is in the area.

According to AirDna, Fennville, MI, Grand Rapids, MI, and Wisconsin Dells seem like good choices.

I understand that, but if you keep it as a primary residence and do some sort of house hacking deal where you rent out rooms, can you get passed that?

You can rent out to individuals, per room and not be a boarding house.