I also have small server in my own office for testing and I can switch to it in short time if necessary. But I have only ADSL connection there and it is not enough for running witness node. But it's an option I have and I can bridge few days with it.Hi, I decided to rent virtual server from @privex, where they hosts servers in different locations and I hope they can move VPS from one datacenter to another when needed.
I have some plans for backup witness server and public node located in Czech Republic. I subsidize running of witness node by my own so first of all I have to work on financial security of the planned servers.