It's time to close my in ground vinyl pool for the winter. However, there is a leak(s) most likely in the vinyl liner that has escaped detection. Several other leaks were found and patched but there remains more leaking. The liner is very old and needs replacing (+20 years), but my pool guy says its too cool to change it now. He suggests closing the pool for the winter and replacing the liner in warmer weather. He assures me that my pool structure will not "pop" out of the ground given that it must have a hydrostatic pressure valve, and that I have nothing to worry about. He further suggested that as long as I was going to replace the liner that the pool need not be covered over the winter. I am at a loss as to what to do? Suggestions? Thank you.