If I may build on the recommendation by @PeterWest. If you are employing AT&T or VZW (but not both) at any one point in time then a BR1 would do the trick - it has one radio but provides for two SIMs, between which you can alternate as needed - you can then pick the carrier best suited for any particular location you find yourself at.
W.r.t. the hulu zip issue. FWIW I expect it may be a matter of what one subscribes through - streaming services may indeed be restrictive as to where your IP address is at (the most obvious example is that you cannot stream certain shows on Netflix if your IP address is located in Europe), and similarly if you are streaming TV shows tied to a local cable subscription they may be refusing to serve you if your IP address is not the one at the subscription home address or is not in the subscription ZIP code.
Employing VPN servers are a common tactic for avoiding these restrictions (to state the obvious), and the streaming service providers attempt to combat them with varying seriousness and success (also obvious). Consequently, many of the well-known VPN services or cloud services (if you contemplate installing your own FusionHub as a VPN server at a certain location) are blocked as a matter of routine by the streaming services.
So, in evaluating your strategies be mindful of the possibly short-term usability of such a service, or evaluate whether you can install a Peplink Balance at the ZIP code (with an ZIP-code appropriate ISP) and then set up a PepVPN connection between your RV and the stationary, private Balance VPN server.