edit: ah, it sounds like reliable internet isn't available where you are. I guess this won't work for you then.
This isn't what you were asking for, but I think it is better. I use wifi for calls and texts when at my parents' place in the backcountry, and overall it is far cheaper and more reliable.
Either get the cheapest smartphone that supports wifi calling and use that once your house is built, or port your (smartphone only, sorry your dumbphone can't do it) number to google voice for a one time fee of $20. Then install the google voice app on your phone and set it to default for all incoming/outgoing calls over wifi, plus texts. This is all via the internet, so no minutes or data plans enter into this so the lack of cell phone bars doesn't matter so long as you are at home.
You can actually drop service on your phone at this point if you want, or keep it for when you are in town and have better reception. You can also downgrade to some cheap red pocket $5/month plan if you just want cell tower service every now and again, while mostly relying on your GV/WiFi calling/texting.