I would say multiple units. I don't know what the power requirement is, but 6 will be stretching it too much. Where I'm living 5-6 amps is the supply. So I try to split everything into different outlets as much as possible. This reduces the chance of over heating at the power outlet.
For matching this load one will probably need a setup with a large battery(s). You will have to manage it separately. Consider one unit setup only if you are planning to install a dedicated power setup, instead of just connecting to a power socket on the wall.