A couple of other work options that we chose are the sugar beet harvest, driving trucks for the farmer and Christmas tree sales. Both jobs pay well and are short duration, 2 weeks and 4 weeks, so you don't get bored or burned out. Those 2 jobs pay for 6-7 months of our full time expenses.
Edit (Don't mean to understate the work involved, truck driving is 12 hour days, tree sales means loading and tying down 2-300 trees on car roofs.)
Greg