I have made it a point to make almost all my weapons .22 for that reason. I have 5 rifles and a pistol that all shoot .22 LR. I have plenty of ammo.
My problem and it is a big one is I live in a city and getting out will be difficult. I fully realize that it will make my chances less but I have family that cannot be easily moved and I cannot just leave them.
Scopes are great and very accurate, but they do get bumped off and have to be re-sighted in often. Not something you will want to do with a limited supply of ammo.