I winterize my TT myself and then store it in an unheated giant old warehouse.
In the spring for the last 2 years I have had the dealer de-winterize because it includes sanitizing the the lines and tanks.
I also get a bearing repack because with the mileage we put in I figure it can't hurt.
The dealer had a $35.00 roof inspection and caulk touch up but this year that's gone.
They are pushing a roof clean and rubber treatment. Every hear of this? It's not real expensive but it could just be totally worthless. I have never had any roof or any other type of leak.
See link to ad:
https://www.wilkinsrv.com/rv-service-coupons