My apologies; I ‘deleted’ my reply.
I don’t know how to find the temp files, but I had questions and suggestions for avoiding the issue in the future. None of which would help with your current dilemma.
Reading over what I originally wrote, I felt the tone of my reply was off, so I tried to remove it. Sorry for the confusion!
If the program is still running with the file showing (which is not how Fetterman's initial post reads) than perhaps you could try saving it in a smaller format, ie: mp3, or maybe on a flash drive if the laptop hard drive is actually too full.
Something doesn't seem right to me; there may be a glitch in the software, but I don't feel like you have posted enough info about the circumstances to know.
Anyhow, it sucks to lose important files, and you have my sympathies.
Another thought, as a last resort, perhaps you could connect to another computer via line/headphones out, play the file and try to re-record the sermon?
Good luck! vapors