OK,
I lived in a 30 foot fifth wheel I bought brand spanking new in 1999 for over two years.
The trailer was situated in a mobile home park that had electric, water and sewer.
Granted it was like an RV park.
I never had any of the problems, bugs, rat, mice or any other things happen that seem to get driven into the ground here.
All I did was park the trailer then I used cinder blocks and frame jacks to steady it.
I bought a small shed also to keep the inside uncluttered.
The temps went from 90's to -1 during one very cold season.
Never skirted the trailer added extra heaters or anything else.
Never had frozen plumbing in the trailer.
Never needed to heat the sewer piping.
Never shoveled snow of the roof.
I got rained on, snowed on, it got hot, it was really cold a quite few times...did fine.
These trailers are much more durable than we might think.
The least most reliable item was the water heater.
It did work fine for over two years, yet didn't make it much longer than that.
*
BTW
That fifth wheel I spoke of above...was just sold by us this past April.
It was in above average shape and I frowned as the new owner towed it away.