Part of disaster-planning is to figure out the blast radius. If it’s just your house, or a small brownout, then something like this would work. As long as you plug your router so wifi can keep running, or maybe you can tether to a cell.

If it’s a neighborhood-wide outage, chances are internet is down and possibly nearby cell towers. Most of them are suposed to have battery backup.

We once had a six day outage and it turned out the cell towers ran out of power after a few hours. Phone companies brought in diesel generators just to keep emergency phone lines open (with degraded data). All the food in the fridges had to be thrown out after day 3.

It was right after that when a lot of people went and bought gas-powered generators as home backups. Many signed up for satellite data. Those who could afford it got solar panels and home-size batteries.