Another idea might be to have solar panels or wind turbines up top and geothermal below. Both could use molten salt storage, from which energy is generated on demand.
This way, any heat generated from geothermal would not be wasted.
It's just a matter of whether the economics of drilling and maintaining the bore hole would be worth it.
I guess you could use the heat as you go to try to cool it enough to keep drilling over a few years.