Planning a golf trip for ~20-25 guys for around October this year - any recommendations of great courses, locations, or places to stay (looking at airbnbs) ?

Vilamoura, Portugal. 
Play all the Dom Pedro Courses and stay at the Domes Lakes.
But also, the Algarve has amazing parkland and links style courses which are really well kept, with stunning ocean views and great places to stay. And this can be done on any budget.

25 is a lot to coordinate housing for. Of course airbnb or onsite lodging best choice. Vegas obviously easy with a large group and plenty of other things to do.

October a bit shorter days so stay south for more golf. Otherwise Wisconsin top of my list. Just go Scottsdale probably easy too

Can’t go wrong with La Quinta in Southern California. PGA West is always my go to

Scottsdale - Quintero (kind of far), Grayhawk (Raptor), WeKoPa (both courses), Troon North (prefer mountain but both are good)

hilton head island, certain places you stay will give you free golf at nearby courses