When I replaced my furnace a couple years back I asked for a heat pump - a previous house had it and it worked great. Turns out my contractor didn't ask the right questions and so mine only works to 25F - it still outputs heat below that, but not enough to keep my house warm and so I use the backup furnace a lot more than I want to.
A previous house the heat pump was sized to work to 14F. They make them that will work down to -25F, but since it gets to -30f where I live (about once every 10 years, but that is enough) we need a backup system so is probably isn't worth getting a system sized to as cold as possible.
Ground source heat pumps are a common option in rural areas - they cost a lot to install ($50k - and this is the cheapest version that needs a lot of land thus rural areas). They are likely to pay off if you live in the same house for 50 years, but the initial upfront costs are high (you do get a house worth $10k more than other heat option). Worth looking into if you are young and have reason to think you will live in the same house for 50 years.
It's really amazing how often I hear that same story: poor choices by the installer left the home owner in a bind with a poorly functioning system. The industry (certainly the residential side) really does need better educated installers/planners.
Even as a homeowner who's a bit of an energy geek, it's entirely too challenging to understand the entire space and what options fit one's needs. LLM's help a lot here (if you can trust them!), but it's a funny situation where there's silos of knowledge that are hard to connect.
I'm amazed at these prices, I replaced a propane tank + furnace with horizontal loop ground source for $40k Canadian (+ tax, but government rebate matched that). It's almost paid for itself in about 6 years, I gave more detailed numbers in another reply.
Your setup sounds great, but depending on location in Canada, gas can be much cheaper than propane. I just priced running a gas line for my BBQ, and I'd break even on a $500 install cost after about 40 20lb propane tank fills.
Yes the calculations are different for natural gas, I don't have that option. Rural properties here (south/central Ontario) typically use delivered oil or propane supplemented by firewood.
I recently thought about running a BBQ gas line from my main 500 gallon propane tank, but with delivered propane close to $1/litre right now and a 20lb tank holding about 18 litres there's no saving over just using with the portable tanks. I prefer being able to move the barbecue around too, although I probably would run a line if I had an outdoor kitchen type setup.
Maybe? Conservative (i.e. any number assumptions here are all biased against the space heaters) napkin math: My gas furnace uses something like to 300 kWh per day to keep the house 30 degrees (C) above the outdoor temp. If I only need the space heaters to supplement an extra 5 degrees, that's actually pretty close to 2000 continuous watts.
A previous house the heat pump was sized to work to 14F. They make them that will work down to -25F, but since it gets to -30f where I live (about once every 10 years, but that is enough) we need a backup system so is probably isn't worth getting a system sized to as cold as possible.
Ground source heat pumps are a common option in rural areas - they cost a lot to install ($50k - and this is the cheapest version that needs a lot of land thus rural areas). They are likely to pay off if you live in the same house for 50 years, but the initial upfront costs are high (you do get a house worth $10k more than other heat option). Worth looking into if you are young and have reason to think you will live in the same house for 50 years.