Two things.
First, all DirecTV has to do is add all possible channels,2.1 - 83.8 to a single faux secondary market associated with a zip code that does not really exist, such as 00000 Simply list "Regular Schedule" in the guide 24/7/365. Then a user could simply use the channel guide set up menu to pick the channels that actually exist where he lives. That way, at least, every channel a person could get would be tunable without all this pretend you live in Reno and pretend GET TV is really ASN ho ha.
Second, and I think this will happen, is to remember that these channels, except for local commercials, are the same all over the country. You know what they do with ION? If you don't, well you get ION on whatever channel it is locally, but it really is not you local ION. It is the national feed. So do that. There are, what, 20 .2 channels. Just put them all up in SD from the national feed nationally. Lots of SD bandwidth available. Toss a few $$ to the local station for people not seeing their local ads.