If Monarch were to pull out of EMA and LBA, it would be interesting to see if they would reposition those aircraft to other bases or do they have four aircraft where leases are due to expire before next summer.
(Not including the current 757's that are already leaving.)
Closing EMA and LBA must be a difficult decision if this happens, as it must have cost the airline a fortune to set these bases up. They got wet leased 737's in at very short notice to build these hubs up and got a lot of bad press, caused by using these wet-leased aircraft and lacking the service Monarch customers expected and all the issues with these aircraft going Tech. Then obtaining Airbus' A320's at short notice use at these bases. I would imagine they need to operate for several years from these bases to get a return on the investments they made.
I personally think Long Haul could also be pulled before next summer and get someone else to pick up the current schedule for next year or buy seats on Thomson/Thomas Cook/Virgin Flights.
If the lease on the A330's is not due to expire soon, I doubt there would be much problem to sub-lease them on to another that needs capacity.