General consensus is that soft covers are not recommend for our Airstreams. There are some new brands on the market that are advertised to be safer for the finish. Camping World sells them. You might consider a portable garage as a temp measure. In my experience the tarps used in these only last about a year. Less if a good storm comes along.
WBCCI 10656 Southeastern Camping Unit
Associate European Unit
2006 Safari LS 23 ft
Formerly 1964 Bambi II
"I got a fever and the only prescription is more cowbell"