The "only data" frequencies that match are LTE, and you have to have a 4g LTE signal available.
That is going to make your efforts pretty futile because when the 4g signal fades, the AT&T / T-Mo data frequencies are on other frequency bands than what the Verizon phone supports.
I found that out the "real hard way" once at a friend's funeral. Stayed at a hotel in Windsor, MO, USA and there is no Verizon presence in that town at all, nowhere..... I complained to VZW support ( hotel WiFi chat ), but all I got was a bunch of Flim Flam about how their "map shows solid coverage"... uh huh, and I have more money than Donald Trump...
AT&T was solid there, my friends with AT&T, T-Mobile, Cricket, ( all sharing partners ) had good solid service.
Those of us on Verizon were very upset, and for me, it was the 1st time in 20+ years that I was in a town w/o any coverage at all. No SMS even, that is how bad it was. Usually SMS can sneak thru... but when I left that town headed home, I had SMS messages "unsent from the previous day".
You have to remember, Verizon phones are CDMA, not GSM, and the 4g LTE band is the only GSM data band that a VZW phone will work on.
