You might consider an Electro-Warmth mattress pad. This creates the heat underneath you, whereas an electric blanket makes the heat above you. Since heat rises, the mattress pad is more efficient and IMO does a better job of keeping the sleeper warm. They have a 12V version, too.
Make sure your rear-stored battery
doesn't take too much weight
off the hitch. Hitch weight
should always be about 10% or more of the trailer's total weight
. If the weight distribution is not kept to the front, you could end up with severe trailer sway that could cause you to wreck. Sway with such a small, lightweight trailer, you ask? Yep... voice of experience here, with my minivan I towed a 400# 4x8 utility trailer improperly loaded with negative hitch weight, and it acted ok for 3 hours of highway driving but suddenly, boy did I get a scare! All I did was slow down for a turn up ahead, and that trailer started whipping violently from side to side!
BTW, if you can add brakes
to that Pod, they would be an excellent safety addition. In a situation like the above, activating just the trailer brakes can help bring the trailer back under control. And of course when some idiot pulls out in front of you or that big dog (or deer) dashes across your path, a shorter stopping distance can make all the difference.