So I'll 2nd bluefish's recommendation of Randy Flannery at Wilderness Escape. But full disclosure we are good friends I knew Randy & Sharon before they had the lodge in Maine. If it means anything he gets many repeat bookings and by this time of the year he may not have openings for the baited bear season but you would have to contact him. I always like listening to first timers in camp talking about how impressed they are with their operation, how hard the staff works to give you a good experience, and how they plan to come back.
Maine does have some big bears. I think it has a reputation for 100-200 lb bears due to that being an average black bear in many states and that hunters (especially first timers) shoot the first one they see which is often a smaller bear, and that they are one of the hardest animals to judge for size.
The baited season in Maine is at the end of the summer so I don't believe grouse season is open but there are many fishing opportunities and Randy's lodge is right on the lake. Was there for bear last year and yes I did get a 400 lb'er, my first big one, I've taken some smaller ones previously. Planning on going back up for deer this year.
Best of luck where ever you go.