Tmobile is only wifi in BTV. On the drive up 4 from Stockton, there’s a blip in Copperopolis, a larger blip in Angels, and service in Murphys; otherwise, nothing after Farmington. Nothing in BV.
Friends with Verizon have service when hiking in Carson Iceberg.
We have two different cell services. One is Verizon that works great, the other is AT & T that doesn’t work after Murphy’s area. As for a landline, we use Magic Jack. $35 a year, can’t beat that. Grandkids use walkie-talkies. lol