If you want to enjoy foliage, you'll want to arrive a little earlier. Peak foliage in Maine is typically the tail end of September/beginning of October. Trees are bare by November.

The Rockland area might be a good fit for what you're looking for depending on how flexible your definition of "urban" is (population ~7k). You've got Camden Hills State Park right there for some incredible hiking, plenty of coastline to explore, and a decent live music/entertainment scene as far as small-town Maine goes. You're about an hour and a half from Portland and two hours from Acadia, so day trips in either direction are totally feasible.

As with literally everywhere else in the state, we're definitely in the midst of a housing crisis in the Midcoast. You've got a healthy budget, but just keep that in mind when you're looking for housing.