Re: What's a couple of hundred meters between friends?
"TL;DR version - there won't be enough heat to make it worth while."
Which is the same reason why geothermal plants aren't worth building(*), except in a few very limited cases where you're on top of a magmatic hotspot such as Iceland.
(*) The heat they produce is low grade, resulting in thermally inefficient production and the heat output declines substantially over time no matter how many new boreholes are sunk. On top of that you often have "interesting" side effects - the Icelandic hot lake being one, but "The Craters of the Moon" at Wairaki being a more common counterpoint that's not particularly beneficial unless you happen to be a tourist (plus you need to get rid of the bore water, which is invaribly highly polluted with dissolved "stuff", either by reinjecting it into another bore (high energy requirements) or dumping it in a river with associated fishkill, etc.)