Guys - Have spoken with Jimmy Davis at TM about this after I got my 2619 last year.
He cautioned that IF I bought a cover it should be breathable, and he notes that the trailer is meant to be weather proof and sit outside in whatever mother nature has to offer...
Today for example, it's snowing here in Portland, Oregon... Glad I caulked that roof seam behind the awning a few weeks ago!
Gregg