My son was able to book the last 2 seats on a Southwest flight so we only lost a day of a $500/night AirBnB. Luckily, my son uses gmail so we got the confirmation w/ a check-in link OK. We lost our car rental reservation because Alaska's idea of a replacement reservation arrived 32 hours later and Budget only holds for 24 hours. Even the SWA was 26 hours later, but somehow Priceline + Thrifty found a car.
So a shitshow could have been even worse if the 2nd outage had started earlier & my kid had taken my advice to de-google. My sister & parents also use Fastmail due to my advice, but aren't as dependent on timely email.
One thing that did save me is that I brought a notebook which has all my old email. Almost left it behind, but it's 2.8 lb & 1.61 cm thick. Smartphones still have their limits....