Magma is not necessary for geothermal. Regular fracking methods suffice to get to sufficiently hot strata. Once at the right level, you drill two holes horizontally in parallel for several hundred yards and pump cooled water down one and get hot water out the other. It stays liquid under pressure and boils water in a heat exchanger at the surface.

The tech is still at pilot stage, but with no fundamental problems to solve. The important question is whether it will be able to compete commercially with solar and wind, which costs are still in free-fall.