You don't have to go all the way in to be able to obtain energy. Hawaii and Iceland both have geothermal power generation facilities; it's very doable.

Maintenance costs overrun any efficiency gains by using geothermal even under optimal conditions, so unless there's other reasons to use it, ideological or economic, most companies will stick to the local grid.

There are some really cool innovations with graphene coatings generating power as hot saltwater flows over it, simplifying power generation by basically creating giant linear convection flows(, as well as graphene coatings on bits to increase durability.) The technology has a ways to go to compete with solar or coal or gas if grid proximity isn't a problem.