I doubt your grandpa is going to do that. No, he’s probably going to buy the “smart” drip pot and be proud of his purchase.

Just recently set this up, but with a zigbee energy monitoring smart plug. I recently got a Technivorm Moccamaster for $175 that has a physical toggle switch for power and another for the hot plate. Turn them both on, grind the beans and fill the water tank the night before, then set up an automation to turn the smart plug on when the lights go on in the morning, and boom, coffee is ready by the time I stumble into the kitchen, narrowly avoiding death by tripping over hungry cats.

Since it's an energy monitoring smart plug, I could add a bit to the automation to cut the power when the watts drop after the float switch in the water tank automatically flips and turns off the boiler, or I could just tell the automation to cut the power 5 minutes after turning on, OR, as I discovered when I messed up the automation, the Moccamaster can actually physically FLIP ITS OWN POWER SWITCH OFF automatically if it's been on for over 100 minutes because it has a freaking tiny SOLENOID built into the power switch assembly that will mechanically move the toggle switch into the off position, physically cutting the power to the unit, which you'll want to account for in the automation, because it won't work if the power switch is turned off.

Thanks for coming to my TED talk. I mostly just wanted to tell someone that my coffee maker has a tiny solenoid, because no one in my house really cares.

bonus points for z-wave/zigbee only devices without wlan/bluetooth connectivityy

Outlet timer + dumb coffee maker = genius coffee maker...but cheaper, and simpler and doesn't randomly break because an update fucked something up in HA (again) so your automation isn't running today.