I use my phone data for browsing/watching YouTube videos if that's what I'm killing time with at home if rebooting my router doesn't fix it, after calling my ISP to verify the outage.
This is assuming I'm not already doing something else when it goes out, but I won't notice much because my phone is also my background podcast device and I'll turn off wifi on that if my home wifi router is acting wonky anyway, even if my wired stuff is having no issues if I don't feel like logging in to my desktop to reboot my router.
Now if that goes out, I have problems, because I am technically on call 24/7. I'd probably have to ask a neighbor if I can use their wifi so I can message my boss saying my cell service has ate the dust. I would probably use that time to back up stuff on my phone and perform a factory reset to see if that fixes the issue.