Welcome to the RTA Forum!

That really is far to broad of a question - the pros/cons of a trip to say Florida in September are vastly different than the pros/cons of a January trip to Montana.

In general, Fall/Winter trips are a time with reduced crowds compared to the summer, but in many cases you have cold weather and/or limited access to areas. But again, you'd have to get into the specifics of where and when you are looking to travel.