I hate to say it, but I don't think the Liberty is going to get it done. Even a small toy hauler will be over 5k lbs. Enclosed trailers can be converted, but they tend to be built heavier than an rv so you would need to be careful there too.
You could either upgrade your tow vehicle, opt for a non th and leave the bike at home, or go with a pop up th. Regardless you still need to take some precautions in bear country. We do a week in the Adirondacks and occasionally the Catskills every year. Never worried much about bears. I see the DEC campgrounds mostly have bear boxes now. People tent in those places, just be smart.