Also sometimes you can get moved from one temporary place to another. It depends on what's available. As a non addict, they may be lucky enough to be moved to a room in a better place that isn't filled with addicts, when one comes up. If their MH gets destroyed by the living circumstances, inform the council because it'll give extra priority points, both for a permanent place and for eligibility for a temporary accommodation self-contained flat. I know that sucks but it's the world we live in. You have to be almost dead to be eligible for help. I don't know if being a refugee gives them priority points.
There's no guarantee that the permanent place, when they get one, won't be filled with addicts and undesirables too. They have to live somewhere and it's often in social housing.
Social housing can be wonderful, offering a secure tenancy at low rents, in a well maintained building with reasonable neighbors. It can also be a hellhole with noise, intimidation, antisocial behaviour and a mouldy property with a damp problem that can only be realistically fixed by knocking down and rebuilding.
It's luck of the draw to a certain extent. They do unofficially assess people and try to put nicer people in nicer blocks/areas/estates. Their assessment isn't always accurate though, people can move their partners in etc and people can change throughout life. Plus, the issue of availability.
If you can't afford to buy or if you want a secure tenancy or can't easily afford private rental, it's the only option though.
If they don't like where they end up they could either try the home swap service for social housing or try to better their situation through a higher paying job, opening up buying or private rentals as options for them. If they're young they have time for career progression, if they're capable.