Would you even have gas for it to burn if there was no electricity to run its meter?
Many rural houses have tanks on site because there are no public gas lines to connect to. My house has a 1000 gallon tank and is not vulnerable to the above, for example.
eg: https://en.wikipedia.org/wiki/Natural_gas_storage#Pipeline_c...
There may be more than a day of capacity just in the pipe network.
I'm sure there are exceptions, but I've never heard of one.