There is a diminishing return for high tech systems and insulation gives the best bang for the buck. High tech means high cost and high maintenance. Either you do it or you pay someone else.
Passive system have been in use for centuries. However even they need control over the land. Those snazzy solar panels aren't going to do much good if a condo goes up in front of them.
I'm not sure how geothermal reacts to changes in ground water levels.
That's the nice thing about geothermal. The technology is quite simple, basically a glorified, up-sized refrigerator with a water pump.
The geothermal HVAC in my current house has been in place for 10 years and has never needed any servicing short of a vacuuming and filter cleaning. There is a compressor and a water pump and an ECM fan motor, all absolutely trouble-free. No burners, no ignitions systems, no exhaust or intake piping to worry about. This is why I chose geothermal again for the new house.
Geothermal works best when the ground loop is kept wet. That gives the fastest heat transfer from ground heat to loop, and also tends to broaden the effective ground area in contact with the loop as wet soil can draw or release heat from much further away from the loop's piping.
The loop (in the new house under construction) starts in fairly dry high ground but from there heads directly towards a drainage swale that is usually wet most of the year, and from there to a point just short of my shoreline on the St Lawrence River. I can dig deep in my own land right up to the shoreline, but digging down into the river bed itself is "discouraged" for environmental and marine life habitat reasons.
If you are on water, you could float a geothermal piping coil out from shore and sink it to the river bed if the water is deep enough. Unfortunately water levels on the upper St lawrence typically drop by a meter or so from summer to winter, and in winter the water level close to shore is not deep enough to just float out a coil and sink it to the river bottom and still have enough depth to keep well below winter river ice. You also risk damage from boaters dragging anchors if you are in a popular navigable body of water, as I am.
So, mine is a ground loop buried deep in in wet land right next to the shoreline and well below river water level. That loop will always stay wet and should never have heat transfer issues.