Have an auto-move setup for players that have been ideal for say 10 days. That is, if someone doesn't move within ten days, their plane you be auto moved by the system so that the game doesn't get stalled for months and months.

I know, some of you are going to say "I don't like that idea because I go on vacation a lot". Well, that isn't fair for the others and you should be wrapping up your games anyway before you go on vacation.

A two week auto move (14 days) seems more than reasonable I would think.