Much depends on where the leak is and where the water level stops. Anytime a liner pools looses most of its water, there's a risk of the liner and/or supporting shell structure moving. In addition, covered pools have the additional tension of the cover that can actually help to pull the walls inwards as well if the water gets too low. So if it's still covered I'd say remove the cover. Then watch the water level closely. If it stops draining, or stops about halfway you may be okay. If it continues to leak, hopefully the tear isn't too deep or too fast to where rain and snow will help replenish the pool a bit. But if it drops to the bottom, you'll probably want to address the defective area right away and fill it back up at least to below the skimmer or where you typically adjust the water for closing. Keep us posted and let us know what you discover. Good luck!