Jet2 have had their own ground handling operation for nearly 12 months now, they also have dedicated hangars at Leeds and Manchester. The only thing that Jet2 would want is the 737MAX order. The most (and until recently only) profitable part of Monarch is the engineering business. Greybull have been rumoured to buy Atitech to create a large maintenance business.
Unfortunately I think that the only way forward is for Monarch to be split up.
easyJet will buy the slots at LGW & LTN.
737MAX order will go to LS
Maintenance to be merged with Atitech to form a larger business which can be sold off.