It's interesting to theorize about the best way to deal with an oncoming thunderstorm. I love thunderstorms, but have decided to not sit out on the porch and watch them while at home. Inside my "faraday" cage, at home, I don't worry about it, as the house is built of massive steel posts and trusses, bolted to a rebar filled slab. The roof
solar collectors and their metal frame are grounded with a heavy wire bolted to the iron house frame. A significant ufer ground system grounds the power system with multiple 1/2" rebars buried in the slab and footings.
The trailer has foil backed insulation between it's double hulls, but I doubt it would carry many amps to the frame. It might even act as a giant capacitor and store the charge. Best would be to sit in the TV and attach jumper cables from the frame to a chain link fence, heavy steel post or steel water pipe, just to make the best of what was available, to ground out the charge. Of course, while getting set up, the strike will hit me as I carry the jumper cables or touch the car body and ground it myself.
From what I understand, the highly negative charge of the surrounding air, just before an actual strike, can be grounded with a lightening rod. This might be a steel car body, or a golfer in mid-swing or a tree, etc.
I'm not a golfer, but if I was, I'd refrain during a storm. It seems hiding under a tree for shelter is also a bad idea. Even if you avoid the strike, the tree gets blown up and parts
fall on you.
I think I'll sit it out in the trailer, watching through the window and marveling at the power. My
awning frame might become the lightening rods, or the TV antenna might, or the air conditioner and it's wire, or the
porch light and it's wire. Then I'll be careful not to park where the flash flood might sweep the whole rig away.