Business requirements are very different than a normal RVer would have to deal with. Since this is really a "How do I manage my business needs" it likely should have been started in a thread appropriate to that topic. If you are getting paid to be on the internet, you should have worked that into your budget before you began the work.
It appears that you now want to bemoan the realities of cellular internet and try to find someone to blame other than yourself.
I don't see where anyone has done, or is doing, anything wrong.....except, possibly, you.