There seems to be differing answers to the "extended" question. From my own experience trying to get home fusion...extended coverage won't get you Hf, you need to be in top tier of coverage to get HF. However, you might be in a good situation for a millenicom/external antenna set up.
I'm in extended area and they say I'm not eligible (after saying I was on a previous call). I can get '2bars' 4G with my USB modem and a yagi antenna. When I asked for the URL to the map they were using, they said it isn't public.