I used to get about a mile on 900MHz Ricochet radios, one of which was sitting on a chair in the living room, the other of which was sitting on the passenger seat of my car. Around a mile, the usable data rate would fall below 4800bps, and my NMEA packets would stop going through.

I find it entirely believable that a lower data-rate modulation could get better range than that, even on less power and worse antennas.

And you can do a LOT with antennas on 900MHz.