[jyl]

Go to Verizon.

I have T-Mobile, signal generally okay in urban areas and poor in rural areas. The signal is bad at my house, so they sent me their T-Mobile cellphone signal booster. It helps only slightly. Conceivably one could gin something up with a directional antenna connected to this booster, but I don't think its worth trying in your situation, since you'll still have poor signal in your yard, etc.

I am hopeful that T-Mobile's coverage will improve in coming years, because they've bought so much frequency allocation plus added Sprint's frequencies. In theory they should have enough frequency at low and high band to have leading 4G coverage plus real 5G coverage. In practice, I suspect that will take years. In the meantime, I think you need usable cellphone coverage.