With an in-ground liner pool the water should never be lowered beyond the top of the bottom step in the shallow end. If this pool was lowered to only 1' left in the deep end, it was drained way too far.
There is no good way to remove the wrinkles. Other members with vinyl liner experience will hopefully have some ideas.
Unhook the liner, get a wet vac down as far as possible, seal around the hose with wet rags or tape and fire her up. You may have water behind there so you may have to dump the vac over and over. Use your pool brush to push the wrinkles around.