HI!

It's probably fixable in the spring. I'm assuming that the wrinkles are vertical and not horizontal. If that's the case, the liner is just not perfectly positioned in the pool (very understandable given the air temp when it was dropped) and needs to have that are worked back out into the body of the pool. Unfortunately, that means dumping most, if not all, of the water in the pool.

It sounds like the weather 'snuck' up on your PB and he had to drop the liner under 'less than favorable' conditions. If it's any comfort, you are better off having the liner in the pool and full for the winter, the new liner is supple enough to allow for this.

If you want more on this from me or want to discuss how to proceed in the spring, all you need do is ask - we've got a few months before anything can be done and I'm more than happy to share my thoughts, experience and suggestions with you.