OK, here's what you CAN do, but DANGER! DO NOT DO IT WITHOUT GROUND-FAULT PROTECTION!!! THIS IS AT YOUR OWN RISK!!!!

I used a small hair dryer to soften my liner enough to pull it back into place, slowly heating and pulling. But I have a GFCI socket (all outdoor sockets now must be GFCI by code) and the hair-dryer also has a GFCI plug. When I started, I still had a lot of ice on the pool and anything dropped didn't get wet--I didn't drop the hair dryer.

IF YOU DROP IT IN THE WATER DO NOT ATTEMPT TO PULL IT OUT! DON'T TOUCH THE WATER! Instead step away and walk to the outlet and pull the plug. The GFCI should have shut the current off, but you need to double-check by pulling the plug first.

It is risky to do, even with precautions but I was able to get my liner completely back in the track this way. I ran my drop cord OUTSIDE the pool, using only an outdoor-rated cord and made sure the GFCI was working every time.