Ferres is done at Hudds. What they hold is simply a barrier to other clubs signing him. They won't keep him not playing for 4 years, so the remaining term is meaningless.
The problem is the ability of anyone being able to fit him under the cap when most clubs had finished recruitment for next year. The top clubs will have no space without offloading someone (and getting a player to go at this stage might also be hard), which might mean the likes of Salford are his only option.
BTW unless they're idiots, there's no way Hudds would pay a share of his wages. What he's done would give them the ability to tear up his contract (disrepute and behaviour clauses - wouldn't be hard to prove in court). That means all they'd need to do is agree a swap and he's gone.
I have every sympathy with Hudds and their fans on this - Ferres has dropped them right in it with very little chance of getting a decent replacement for next year.