Using Data Hotspot while Roaming

I travel to Montana several times a year & have for years have used my mobile hotspot (& tethering) on my phone.  I use this to continue working while mobile and have always stayed within my data limit (or increased my data plan to support).  This summer I was told that T-Mobile no longer allows mobile hotspots & tethering in roaming areas.  Well the whole state of Montana is considered roaming.  At the time there was no plan that I could add roaming data so I could hotspot.  There are just some tasks that a phone is incapable of doing and I need to use my hotspot.  Has T-Mobile come up with a solution yet?  I have been with T-Mobile since 1999 and would hate to change cell companies just because of not being able to hotspot while roaming.  Any guidance would be appreciated.