A lot of this depends on your carrier. We have great success using VERIZON SERVICE in the OFF-GRID places we like to go to... Using boosters something just amplifies the noise haha...
I also played with a WILSON CRADEL with an outside antenna some years back and it worked great for my 1G/2G earlier Verizon MIFI box... Now all of that is obsolete especially now hearing that the carriers are all going to the higher technology...
Most of the great cell phone service was only found along the major towns and major roadways...
There is change in the winds now coming at the end of 2019 it seems...
Roy Ken