I come from the opposite end of the TEFL career curve having only recently qualified and started to teach in summer school. I presume that one to one tuition is not an option for you for some reason, i.e. to freelance for the summer holiday period?
I for one am interested to hear what your alternative summer employment options are. My own preference would be to do freelance one to one tuition, where and when possible, but I suppose as a source of income it cannot be guaranteed.
I intend to head out to Thailand soon to work, and a trip back to the U.K or Europe every summer isn't really an option due to the expense.
My previous employment expirience is in procurement, which isn't much use. I suppose getting a job in a bar or similar is a last resort, unless it's located where you want to have your holiday!