unfortunately there isn't another providerYou say your AT&T 2-bar LTE connection works.... maybe you ought to give them a try? I have Verizon where I live but it's not as reliable as Hughesnet and it's more expensive (though now they let you carry over unused data, which is nice).
No Ultra Plan, here. The largest is the Max, with 20/50 for $129.99. I have Pro Plus, which is 15/50 for $79.99, though I'm getting $10 off per month for the first 12 months for upgrading, which ends next month.
Though I can't get the Ultra Plan here, I do find it a bit comical that I could get an additional 5GB per month for $50 more with the Max Plan. $50! I could get 9GB for the same price in tokens!
Of course, I could save an additional $5 with automatic billing. Oh, that's right, I can't.