Most HD-2 stations travel the same distance as HD-1 stations, because they each use 48k of the 96 primary subcarrier. There is an additional set of (lower power) subcarriers which some stations use to broadcast an HD-3 station. These are more limited in range.
It is also possible to have a 96k HD-1 channel taking up the main subcarrier, and a low bitrate HD-2 channel taking up the secondary subcarrier, but I believe this is extremely rare.
As for range, I do not quite know the answer, but I know multiple people on this board have reported reception of HD stations over 100 miles on a consistent basis, so I would presume it goes pretty far. When factoring "range," you also have to consider reception equipment and conditions. A Sangean HDT-1 and a large outdoor yagi (APS-13 or HD-6065) are going to do a better job than a car radio and a whip.