When we first moved to Kamloops, we lived in a 24ft trailer for two winters and one summer. It was a total of about 20 months while we built the warehouses and house. Our children were a bit younger than yours. (4 and 6)
We found having an awning room enclosure gave a good inter-space between the trailer and the outside. (Of course, these structures are only good if you are not moving around.) The awning room enclosure was a place to remove boots, shoes and hang wet items including laundry. We covered the ground with astro-turf. It was also a good covered sitting area outside the trailer. The girls used to play in the area during bad weather.
If I live like this again, I would build in a number of outdoor areas for privacy and fun activities such as: fire pit, barbecue area, sitting and eating area, portable sauna, plunge pool, etc. (Getting people comfortable living outside will make living in a smaller space more comfortable over the longer term.)