Replace AT&T MF279 wireless router with a Nighthawk MR1100 4G LTE without changing plans

[jj57]

Purchased a Nighthawk MR1100 4G LTE mobile hotspot router for AT&T off of Amazon as my AT&T MF279 is flaking out.  Transferred the sim card and turned the Nighthawk on.  After it cycled through a message appeared that I would need to visit an AT&T site to activate it.  I had previously spoken with AT&T as was going to upgrade my MF279 through them.  Was told if I did that, it would require me to change my plan which would downgrade my 150GB to 50GB.  I come right up to the brink of 150GB most months working on a CAD system remotely and streaming, while breaking right through that a few times incurring additional charges.  There is no way I can even just work with a limit of 50GB.  I live in an area where there are no other alternatives to the internet with exception of satellite service.  Is there some setting that can be made on the Nighthawk so that it will not require me to activate it with AT&T?  Or is there another way to activate it without requiring a change in plans?

Thanks in advance