We tore down the 75 year old farmhouse (more like a two storey shack that had a porch added to it) and put a single wide on piles. Dad added a sizeable family room on the rear door side. Insulated skirting was used under the trailer. Water froze until Dad figured out how to insulate pipes and to be safe added heat tape which was plugged in for cold weather. It was the best made brand we could find. Dutchman out of Manitoba.
When we left the farm, we took the trailer with us as we were moving to a town where you could buy your trailer lots. While we were waiting for the lot to be prepared, Mom and Dad decided to buy an ATCO doublewide and have it placed on a basement.
Both brands were well built, but were still trailers.
While working for government agencies, I lived in several government trailers of various types. If well maintained, they were serviceable, without service, they deteriorate quickly and become wrecks.
Another thing to consider is how fast they burn. Very fast.
I would look at modular or stickbuilt. Sell your current house and buy one of those.
