I can't help with the 5er vs TT debate since I own a motorhome. But, living in PA I can offer some winter weather advice. Remember, that you will need to keep the interior of the rig above freezing at all times to protect your water lines. Further, you will need to make sure that all external water lines/hookups don't freeze as well. Will you have electric hookup? If not, your heat source will be all propane and expensive. And, electric power for lights, appliances, will need to come from either a hookup or your generator. How often will you need to buy gas for the generator?
If you buy a full-time set up, and it doesn't work, you can easily set yourself back financially. Good luck.