I'm so glad you've got Wilson inside tonight. I'm sure being warm feels good but maybe he's just so scared of the newness of being indoors that he must be overwhelmed. I bet if he had a place inside to 'hide' he would feel less exposed. Do you have a box that you could put on it's side and maybe throw a towel over it? He might find it safe in there.
And he may have never heard music before but maybe some soft gentle music might calm him a bit.
And then of course, food, food, food. LOL
Maybe special treats like tuna juice or deli meat to distract him.
Hopefully he'll settle in within a few hours and then he might not want to ever leave.