Go to settings then data connection switch your phone to CDME. You will only have 3g but you phone will last a lot longer. You can switch back when you want to use 4g
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You can also select Airplane Mode by simply long pressing your power button. It will bring up a menu with one of the options being Airplane Mode.
As for getting LTE only, there is a way. Dial ##program(7764726). When it prompts for a password, enter 000000. Go to test mode and hit next a couple of times (don't recall how many) and you'll eventually get to a menu that, among many other things, has an option to change your cellular network. You can set it to LTE only. The only downside is you can't make phone calls since they're done over 3G. But, if you don't need phone calls but have a 4G signal, there you go.
For the OP, you can go to airplane mode and then enable WiFi. This will let you get all your data and such over WiFi, but your cell radios (including the phone) will all be off. If you use Google Voice, you can get an app called GrooVe IP that will let you make unlimited phone calls over data (WiFi, 3G, 4G) using your Google Voice number. I have it; well worth the money:
An expensive solution would be to purchase a Verizon network extender. That would give you service in your home.