Diesels are better at waiting than gas engines. But still put it to bed with the tanks full so they don't "breath" and collect moisture. If you can, get a can of "Fogging Spray" and try to crank the engine without it starting. This can be a trick with a good diesel, but a boat guy (fat chance you can find one in Maine ;))will have a good idea what I mean. Then, disconnect the batteries either by switch or by pulling cables. Be cautious with the switch method. Some manufactures put things like the CO monitor or the radio keep alive on the wrong side of the battery switch. (Run into that with bilge pumps all the time.)
Once you have that all settled, go get a couple of (one for the main engine battery and one for the house bank) little solar battery chargers to put in a south facing window. These can even keep a battery topped up just by using the sun both days it is out during a Maine winter.
Before the depression, I did this for a lot of performance cruisers. It always worked out well. My latitude is still about the same, but I can drink the bay and things don't rust as fast. But the only lobster has to get flown in.
Matt - he misses the tide