How should I protect my naked Argosy in the rainy season?

[GuitarMatt]

I have a 1974 Argosy 28 trailer which I just brought home last week. The end goal for this trailer is to trip around the California coast and wine country, hopefully one weekend trip a month or so, and one or two longer trips a year. Since this is a pretty modest goal compared to some, that is to say short distances in mild weather and never more than two or three hundred miles from home, I'm planning on a pretty modest renovation. The trailer has new tires, brakes, bearings, and fully functioning lights, so there's no question of roadworthiness. There is however a question of leakiness. Even though we are dry most of the year in California we do get a lot of rain all at once over the winter. It seems like the best way to weatherproof the exterior shell is to strip the paint and the existing failing caulk then check and replace failing rivets before re-sealing and repainting. The catch is that there is no way I can get that job completely done before the rain starts falling, and the trailer doesn't quite fit into the barn so bringing it inside over winter is not an option. I have a large tarp, actually an old billboard, which measures 19 ft by 47 ft which I could use to cover the trailer.

So my question is, can I start stripping this 1974 Argosy trailer then cover it with a tarp while it's raining, or is there a better option for protecting the naked aluminum and steel over the winter? Or would I be better off just putting off this project until next spring/summer when I will be practically guaranteed 9 months of dry weather?