The males won't let them. Works like a charm but requires LOTS of planning in advance. Ideally, one volunteer can stay throughout the absence, but occasionally an alternating schedule must be set up. The volunteers, of course, must be experienced with all facets of the operation and fortunately there are several long term folks who are ready and willing to do this. There also has to be someone available on a moment's notice to sign checks and dispense funds in the event of an emergency.
Vacations are often non existent for people who have wolfdogs.
Sometimes if you are very lucky you may find some one who knows your animals and routine with them that your animals trust to stay at your house or come by every day to care for them. Even then rest assured you are not going to sleep to well worrying about your babies. If you have to board by all means know well the place you are leaving them and how they really feel about your animals. The wrong place can traumatize beyond repair and could even cost you to lose your animal. If you can swing it financially, leave them there overnight, or for two nights.