A lot of basic infrastructure (such as water) will have diesel generators that would hopefully keep things going. Presumably food production (such as freezers,

A lot of basic infrastructure (such as water) will have diesel generators that would hopefully keep things going. Presumably food production (such as freezers, fridges, baking) could have generators brought in. At that point the key factor in survival is making sure the refineries are kept on-line and are protected against solar storms.