They replaced all of the individual household "feeds" here many years ago: fed a (heavy) steel cable up through the existing plastic/nylon pipe which was connected to a large metal "pig" with outward facing cutting blades. Used the hydraulics from a back hoe to *pull* this through the existing pipe, shredding it in the process. Attached to the rear of the pig is the new plastic feed line.
Last year, replaced the main distribution lines (here... the rest of the city is "ongoing") to upgrade to a larger diameter pipe (I think the new one in this neighborhood is 8" dia). This is done with a similar, though different, process: a horizontal drill is used to bore beneath the street *near* the existing gas line. After a hundred feet (or so), the drill is retracted and *drags* the new feed pipe behind it into the space it has created (goal is NOT to have to dig up the streets).
At intervals, successive pieces of pipe are "welded" together in areas excavated in the road. Then, backfilled and patched.
Amusing to watch the drill in operation -- as well as how they track the location of the drill head (in three dimensions) while it is below grade!
"Ooops!" can be VERY expensive!
The bigger issue is the "surprise" that accompanies the outage. I.e., is *my* furnace broken? (as it *tries* to light but quickly self-extinguishes -- low gas pressure) Or, is it a problem system-wide? (in the wee hours of the morning, neighbors don't take kindly to your calling and asking them if "they have gas")
I *know* the local plumbers made a killing with "unnecessary house calls" for all the folks who thought *their* furnace was broken; only to discover that it was a supply problem! "That will be $120 for the service call, please..."
As this is such an exception, we later decided that it didn't warrant keeping an alternative heat source on hand (white gas, propane, electric, etc.)
[I suspect these alternatives are a source of more problems than they are worth!]If push came to shove, we could have resorted to lighting a (wood) fire. Or, an electric blanket (why get out of bed if you're going to be cold?).
Stove is electric so we could still cook, make warm beverages, etc.
Or, start the barbeque...