The fold-down campers I had for 12 years were always stored in an unheated building for 9 months of the year. They looked great over time. Our current TT is too large for the storage I'm willing to pay for--so it is outside in a secure tree-free zone. I'm going without a cover this year--and will update the forum in the spring. I got a lot of opinion and counsel from local RV owners & delears alike. As you can expect, it is a bit like religion & politics. Anyway--I opted to not risk any abrasion or retained moisture. We'll see if the UV has visible effects in the spring. I did put a very good coat of wax on the unit late in the season.
2017 Cedar Creek 38CK Hathaway Edition
2015 Ford F-350 PSD CC 4x4
Full-timing since 5/2/2016
FROG Int'l Rallies: 2012, 2013, 2014, 2015, (2016)