If the network drivers are properly written to handle the power management
issues, and if the settings are correct, I think this ought to work.
In practice, I've never been able to do it, and make it a practice to
disable standby on machines I wish to work with remotely.
I can, though, turn on machines via Wake-on-lan from the off (or, perhaps,
hibernated) state in many situations. I haven't attempted to do this with a
single machine connected to a router, however. I believe it is possible,
though.