Good luck with that. I've been stationary since last October - broken ankle. Started looking for part time work in February when ankle was better - still no luck. Granted, my requirements may be a little strict due to family commitments but I really thought there would be more openings for evening/weekend help.
On edit: Since there are 2 of you, try places like Amazon, sugar beet harvest, gate guards, anyplace that pays a living wage for a short term. For example, you could make enough working at Amazon for 4 months (campsite included) that you could relax the rest of the year and work at site-only gigs. Of course, that 4 months could be tough depending on your physical condition and you would still need to be frugal the rest of the year.