It should be ok. If you're really worried, get a roll of Glad Press-n-Seal wrap.
Works pretty good for keep a majority of moisture out. However, the real pain is the water in the bearings and every other nook-n-cranny on the truck. If you don't get the water out, things will start rusting. It's a maintenance nightmare when you run in the wet. Be sure disassemble the hubs afterwards and hose 'em the metal parts (kinpins/axles) with WD-40. If you have an air compressor, I would hit it with that as well.