I am on PHPFog for my front-end and with an AWS RDS back-end. I managed to survive this incident without an outage (I am on U.S East as well), although I did get some horrendous response times from RDS for about an hour there.

PHPFog are on AWS and I pay them to make sure they have the redundancy worked out. If they don't, I would yell at them until I got some money back.

I am considering configuring RDS for Multi A-Z, but need to research it a little more first. From what I can tell you just click a button to turn it on, but there were a lot of people complaining yesterday that the fail-over didn't work at all when it was supposed to.

I also have a bunch of EC2 VMs that do back-end processing and have a load of CRON jobs on them that need to run once every 24 hours. If these go down for a couple of hours then there is no noticeable impact to my customers, they can still log into my service and access their historical data.

I have considered spreading across multiple regions etc but at the end of the day it's just too expensive for the small increase in reliability.