how much maintenance does a GPU or ASIC rig require? Is it feasable to rent some warehouse space, set up some rigs, and leave them there for weeks/months on end? I move around a lot but want to mine so renting office space seems like a good option.
I'd not be able to say as accurately as someone with several rigs or months more experience but..
So long as you had remote desktop access to your rigs, checked on them every once in awhile via that, and remote rebooted them time to time, it would seem possible. Granted, this requires that you have stable clocks/settings, which requires a deal of configuration. If the power flickers, or goes out for a few hours, you can set your rig to auto boot as soon as the power is restored.
So, it might be feasible, but I personally couldn't say for sure.