We've gone South from Ontario for the past six years and by simply looking for a 3 day "good weather" window have avoided having to drive in snow or ice. If we did get into weather, we are quite prepared to stop and wait it out. We refuse to travel when roads are icy or snow covered.
As to motel stays, we do not use motels. Like yours, our rig is winterised and stays that way till we get to Georgia. We simply carry two or three gallon jugs of water for cooking, washing and flushing and that works great gor us. Incidently, we pull a fiver so you would have it even easier in your motorhome. Just have a full load of propane when you leave. In fact we use WallMarts and Flying J's as campgrounds open at that time are rare.
As to motels, the answer is yes, you'll find them along your proposed route.
As to the route chosen, in the winter months I would be temted to get right down I91 to I95 and put up with the traffic to avoid travel in the Apalachian foothills!! But thta's just my thoughts.
Whatever you decide, have a safe and enjoyable trip.