4 winters now, i have drained my water down about 22 inches from the top edge (which puts it about 2 inches below my jets) vinyl pool vinyl stairs.no problems whatsoever and the pool store's recommendation..

from the standpoint of how much water would be then left in my 15,000 gallon pool? well, at the shallow end, about 26 inches.i have to figure i've drained at about 40% if it to get below the jets. and yes, we do get winter here in my part of alberta canada. (about 45 minutes north of the montana border)