I know that Fat Biking is becoming wildly popular, but I have yet to embrace this idea, mostly because of time and money. I am on a pretty tight schedule and it is hard to add driving to the mountains into that schedule. Consequently, in the winter I am biking inside.
When biking inside make sure your bike is setup for you. I see a lot of people just jump on to a bike and make it work where ever it is already set, that may mean scrunching up and having your knees hit your chin or riding with tip toes. Let's be real people, neither one of those works. Take a minute and find a good working height, 10% bend in the leg at it's straightest point.