A runflat tire can be repaired just as usual: I had mine done a few years ago, still running with no issues. I guess you can even apply the mobility repair kit to it if you feel you need extra distance to cover.
I had the tire monitor warning pop up while driving home after a journey, dead tired, late at night. I found it extremely comfortable to just follow the system's suggestion to take extra care driving and put off the solving till the next day then.
Actually, as it turned out a slow puncture, I just kept pumping up the tire once a month until repair.
In a heavy traffic city it's not only uncomfortable/dangerous to fix a tire on the street. It can be a hefty fine as the cameras don't distinguish your emergency.
People report a runflat can be still used severely damaged, when the mobility kit wouldn't work. And as some movie quote goes: "-Damn it!!! -I hope you have a spare wheel! -I do. But I don't have two.".