I too have have 2 days of iCloud downtime here in the UK, however I was lucky enough to set my email up in a way that allowed me to still receive emails during this period. Otherwise I would be looking at large losses for my business like some of you.
I thought I would share this method of keeping full control of your email for those interested, this applies whether you are using iCloud, GMail, or any other email provider.
The first, and most important point, NEVER use your assigned iCloud email address as the public facing email address. Buy a domain name and have it forward all emails to iCloud (or another provider).
For example, let's say you have a company called Jims Doodadas, buy the domain jimsdoodadas.com, and using a web host or email hosting service, setup an email address jim@jimdoodada that forwards all emails to your iCloud account jimdoodada@me.com. So now you have:
jim@jimsdoodadas.com -> Email forwarding service -> iCloud
Now, if iCloud fails, you edit the forwarding rule in your email forwarding service to redirect to another email, let's say jimdoodada@gmail.com, and immediately you will continue receiving your email. There is always a chance your web host or email forwarding service could fail, well no problem, in that case since you own the domain you can always point it at a different mail service (edit the MX DNS record).
jim@jimsdoodadas.com -> Email forwarding service -> Gmail
jim@jimsdoodadas.com -> Email forwarding service -> whatever you want
The point is, this way you OWN your email address and are not locked in and reliant on one company's service. You can switch whenever you want.