Yes, Maupin is where you want to be. It's the only town actually on the river, has two fly shops, a couple restaurants and bars, a grocery store, and some lodging options. Lots of folks like the rooms at the Imperial River Company and the a cabin at the Oasis Resort might be a nice option. Throw in the Deschutes Motel up the hill on the edge of town and the River Run Lodge down by the Oasis and you pretty much have all the options in town. Expect to pay about $100 a night at most of these places except the Oasis has one cabin (bunks and walk to bathroom) for like $50.
Yes, the weather can get cold at that time, but we almost never get snow that early (or that low). 50 degree days and nights around freezing or normal around that time, but sometimes we start to get a little rain. The river should be fishing well at that time. Bring your sink tips, but you may not need to use them.