Like I said: it wouldn't be a pretty situation but people aren't just going to sit back and accept the destruction of civilization and/or death. People will dig out old textbooks on electricity and figure it out.
Transformers are simple devices. The first electrical gear was a janky DIY affair by modern standards. We wouldn't wait 10 years to manufacture modern switchgear... we'd cobble together literally anything to bootstrap electrical power. It would start off as isolated islands with nearby generating capacity and where enough gear was still operating then spread from there. Major cities would be back online first, followed relatively quickly by medium cities. That might mean that only certain parts of those cities have power initially with neighbors having to share fridges as only every other block is repaired.
Small cities, towns, and rural areas would be proper fucked for a while... possibly a year or more. But before a year was up enough power would be restored to manufacturing that many of those people would install solar grid-forming and/or battery systems.
For whatever it is worth we are better positioned now than in the past. More and more people have distributed generating capacity with solar PV and grid-forming systems like Enphase IQ8 can form a microgrid just from solar energy without a battery (at reduced capacity depending on sunlight conditions). Even 10-15 years ago solar was useless without a grid to tie into so a full grid outage would be close to a 100% outage. 10% remaining may not be a large amount but its a lot more than 0 and enough to move your neighbor's fridge/freezer into your garage and keep food cold for the whole neighborhood.
(Disaster resilience is a feature of distributed solar PV, especially with batteries, that is almost never talked about)