One option would be to try to find a few parent volunteers who are willing to run a fundraiser as a committee chair and not as a board member. You may find that some will help out on a per project basis to help get you through. This is a little unconventional, but might be enough to get you through. In the meantime, you can continue to look for parents who may be willing to step up to the board.
We have a full Board this year, and next year, only a Secretary and Treasurer, but no one willing or able to run events, run fundraisers, etc. We work off the funds from the previous year and fundraise for the following year, so right now, we have money for a year of PTO but no one to run it, only write checks and keep notes. So, I'm thinking we rework the budget to be able to write checks for a limited amount of activities (programs brought in for the kids, but NO social events) for two years. I have heard of one option of turning funds over to the district to "hope" that they use them for school programs, but I do NOT like that idea one bit. Anyone had experience with this problem and can offer ideas, advice, etc."