There really isn't much you can do to improve signal indoors other than get something like (my choice) a 4G WeBoost from Wilson Amplifiers ($250+.) Or a 3G Network Extender from Verizon ($250.) Outdoors might be better, but network extenders and boosters won't do much for outdoor use. You might have to consider these options or others for service satisfaction. Location and environment (buildings and trees and etc...) play a huge part in signal strength.
What phones do you have and what plan are you on? Verizon just release an app that allows you to make and receive calls along with messages while only on wifi, even if you don't have Verizon signal. It only works on certain phones and plans though.
Correct, I assume they have home internet and wifi.
we have 1 confirmation that this new Mathis works with no signal for text and voice