@teamonkey you’re comparing apples to oranges.
American houses are much larger than UK houses and in many places it gets down to -30C here (and up to 45C).
Also, with trailers, usually people drive some distance and they stay put, most often for weeks or months. The trailer itself is much smaller than any house is and uses comparatively little energy to heat or cool.
And if you have a house, you still need transportation. ¯\_(ツ)_/¯