Yeah, you can get electric car chargers where you can set rules something like "Charge whenever power is under 5c/kWh, but try to make sure i've 60% charge by 8am each weekday". Logically you could have a thermostat control AC - we've been playing with that at work because our power goes up at 1pm, so we turn down the thermostat at 12:00 and then turn it up at 1:00 so it shunts some of the cooling a little earlier.

I've never seen a tumble drier that can do it, for some reason mine has WiFi but can't do shit like that. But, yeah I imagine the rule I'd want would be : Dry this anytime in the next 4 hours, and try to spend as little as possible.