The still will be pretty full at the end of the run.
could I let the still cool back down then start again or would there not be any alcohol left to take out
It will be mostly water left- If you have a proofing hydrometer – once you make your tails cut keep collecting the tails until you are down to about 20% and save the tails and add them to the next batch you run.
This way you are pulling all of the alcohol you can out of the wash- saving the tails and adding them to the next run will up the starting abv of that wash.