We face the same problem here: Verizon is the only reliable option. Plus, we're using V's wifi for internet until we're here full time - but with the Google/Verizon incestuous tangle nothing is anonymous. Ever.
My understanding is that some of the smaller outfits (StraightTalk, etc) buy bandwidth from Verizon - to avoid having to put up their own infrastructure; which means during busy times their pipe would be cranked down in favor of V customers... pffft... What I've always wondered is if V has access to the 'data' that runs through their system - even though it's just technically 'space' that they're selling to smaller carriers. Do you happen to know?
Under the radar = use cash and leave your phone at home.
Then again...the gps in your truck will always give you up.