Yeah the grid may be ok except for the short term but if it took out a good portion of the satellites including say GPS that might actually be more disruptive. I just know our susceptibility to EMP (what massive solar flare would basically be) is greater today than any time in the past. If we got hit by a Carrington level event I have a strong feeling that people won't be comparing its effects to that piddly blackout in 2003. Civilization ender no but without much recent historical precedent either.