Even the most expensive covers only last 3 years on Avg according to my research. I have an ADCO which was on my HTT all winter. No problems at all, came off easy and looks great.
I could by 3 ADCO's for the price of one CalMark Cover and be good for 6 - 8 years.
Just my $0.02
As for if this one would fit your TT, Not sure. Doesn't sound like it Best to have at least a foot or two for wiggle room.
Wayne, Kim, Mallory & Abby the Dog
2013 - Jayco Jayfeather - X20E
2012 - Toyota Tacoma DBLCB Sr5 with towing package
Equalizer 10k WD, Prodigy P3 Controller, TST TPMS
2012 - Jayco Sport 10 Popup - Traded