I'd try buckets and battery powered airpumps. I believe they exsist. If not, do you have a friend to hold them? Or even like the previous poster said, If you tell your Lfs your story, maybe they cN hold them.
Get a power inverter to power air pumps from your cars 12v power outlet. Then use like a big cooler that way it will help with stabilizing the temp. You could also use the inverter to power a heater as well