I cover my TT during the off season leaves, dirt, bird droppings and other stuff off the RV. It's very nice taking the cover off at the start of the camping season to have a clean TT ready for the first trip.
My TT is only 23' and I haven't found it really difficult to the put the cover on or take it off by myself. I would imagine the larger the cover the more difficult it's going to be getting it off and on.