Flat we rent is for sale

[trampoline123]

We rent a flat through friends who got divorced. The flat has been on the market for a few months and they've not even had a silly offer. They've reduced and still nothing, they are also changing EAs.
I know their mortgage is up for renewal in Nov so what happens if it's still not sold by then? Do they just have to renew and still keep it listed I guess?

Their mortgage will go onto the providers variable rate, (which will be a lot higher). I don't image they will want to renew with a fixed rate if the property is up for sale as they'd be liable for an early repayment charge when it does sell, which can be hefty.