Well there’s geothermal and there’s geothermal. If you’re going to get ALL the heat (or cool) out of the water that’s one thing.
My house as geo-thermal heat pump, meaning it uses the underground water as the cooling mechanism for the heat pump. We don’t have those giant fan-blade things in the backyard that ramp up like a 747 when spinning, which shed the excess heat (or vice versa for cool) when the heat pump is compressing the gas and using that for heat/cool extraction.
Instead, we get water from the ground (we live on a river) which is a nearly constant 55 degrees. When it’s 10 degrees out and heat-pumps are struggling to extract heat from the air, ours is using 55 degree water. When it’s 100 degrees out and the HVAC is running full tilt to keep things cool trying to dump load, ours is running efficiently using 55 degree water.
It still uses electricity, obviously, but it’s always efficient, which means it uses a lot less at the extremes. Spring and Fall I would presume the difference would be minimal.
So for a geothermal use of acquirer it wouldn’t have to go down as far as you might think, just far enough to extract water and be able to put it back in and let Mother Earth take care of the near constant temperature down there.