Silicon earplugs and a hat with ear flaps. I don't recall the brand name of the earplugs I bought but can look the next time I'm at the store if you'd like me to. They are so much more comfortable than the foam plugs and are reusable so that was why I tried them in the first place. I'll never go back or try anything else.
I've spent 2 28º nights in my trailer with windows closed but the vent open and the vent fan on and blowing the warm air out. Cold when I got in but shortly after I woke up too hot and had to take off the extra sweater and hat to be able to sleep.
ETA: Both nights were with no electric to plug into.