Will a bottle of champage that has been stored on its side in the refrigerator for a year still be good?

I think so because, my mom has like maybe 4 or 5 bottles of wine in the refrigerator from like when I was probably around 5 and she still uses them. Not to drink, she stopped drinking wine a while ago, she uses them to cook. Anyways If wine can last what 6, 7 years maybe champagne can.