We are ~10Km from the nearest village that likely has decent bandwidth, though no idea on the backhaul available from there.
Still 10K @ $30 (AUD/CAD)\m would be $300K+ to put it along existing hydro infrastructure. Wonder what the likelihood of getting 100 households to put up say $3-5K in installation costs would be? That would represent a decent fraction of those reachable along that stretch, and those nearer in may already have DSL.
For reference, the overall construction costs for Australia's FTTH rollout was somewhere around AUD$1000 - AUD$2000 / premises -- probably toward the high end of that scale, but the order of magnitude is right. This would underestimate the cost for a semi-rural area. In Australia's project they use fixed wireless / satellite for some areas where FTTx was not cost-effective.
Another thing to keep in mind is the maximum optical path distance -- from memory this is probably somewhere around the 20km mark from the exchange, probably a bit less, will depend upon the technology used. That still gives you a ~10km buffer region of potentially reachable households around your main fibre-atop-hydro stretch.