The site came back up after 16+ hours of down time.
I was very unimpressed with 1&1 web hosting and their lack of anything approaching customer service. The tech support line rings to India, (I think), they just said they were in the far East, and only has email communication to the people actually working on the servers in Germany. They could never give me an estimate as to when it would be back up. I did however get this nugget of information: "We don't have backup servers."
I will certainly not recommend them in the future, and will gladly post here as I find out whether they actually charge me full price this period. I sent two emails to the specified address to request a credit, but have as yet received no response from either.