My sensei didn't have a dojo for about a year / year and a half. We met in the park and trained a little, and stayed in touch via telephone. Eventually, Sensei Williams touched base with an old friend that he had helped out decades ago when he was trying to get a Tae Kwon Do dojang started. Master Tyler didn't have classes going all of the time, and he insisted that we share his dojang on the nights he wasn't there. We've been there for about four years, and we've been joined by another TKD school as well.
Three schools are practicing under the same roof because of the generosity of my sensei's friend.
Start networking. Go meet people who are martial artists, regardless of style. You might find a mutually beneficial arrangement with another school. Perhaps another group is in desperate need of a dojo home, or maybe your group could move in to help another dojo pay its bills.
And finally, to echo Jill...
PS btw: I'm not meaning to insinuate this is the only way to go, but it makes sense to me and works pretty well at our dojo.
Good luck to you.