We have been organizing a trip each year to Canaan Valley for the past 12 years. We've been working with Mountain Top Rentals for the past 7 years and have always been satisfied with service and the rates. In my opinion, you are better off renting off-
mountain because there is no point in paying slopeside rates for Timberline if you are planning to ski both mountains; you end up driving either way. There are some really great houses off the mountain that are almost half the price of the slopeside places.
We have been staying at Hemlock Lodge off Cortland Road for the past several years and its a beautiful place for a large group. Big spacious kitchen, nice family room, and has 6 individual bedrooms. Most places in the area that sleep that many people have lots of bunk beds and pull out beds which is not good for adults who like privacy. Another plus is that the access road is flat so its a little easier to navigate than some of the other places with steep driveways.
There is a 3 night minimum rental at most places so something to consider is to stay on Sunday night. Skiing on Monday is great because there are no people and terrific deals for lift tickets, especially at Canaan Resort. They've been running a deal where you bring a can of food and you get a lift ticket on Monday for $15. Canaan Resort doesn't get the respect that Timberline does, but I've found that the conditions in the natural snow areas can actually be better after a big dump of powder, mostly because they don't groom it and it doesn't get tracked up quickly.
There is another deal that they don't advertise very well called the Ski the Valley pass. You have to ask for it when you buy it, but it is a 2-day pass that is good at either resort. You can ski Timberline in the morning and then go over to Canaan in the afternoon if you want. The price difference compared to a standard 2-day pass at a single resort is nominal.
Canaan Valley can also be a really nice place to come in the summer. Due to the elevation it is generally a lot cooler than most of Virginia and the rates are very low. There are a lot of opportunities for hiking, biking, or just relaxing in the woods. It can also be a good time to scope out potential houses that you might want to rent over ski season.