Skeleton Lake has been productive for me in the past, never been this late in the season though. Lots of points to work and little bays to troll across. Three Mile Lake is not too far away, it is a fairly big lake also. I have spent some late season time on it with some pretty good results. When you first come in on Dee Bank Road you see the river that runs in from Lake Rosseau (also a good lake), there is a little parkette right there and you can cast for them right from shore, I'm pretty sure they stage in that first bay for the winter.
Check out this website, it shows most lakes in the region.....good luck.
http://www.experience-muskoka.com/lakes.html
Bogz