The ION affiliate is like that in a lot of areas when you look at the list. The CW networks in Miami and San Diego are on CONUS and were, at one time, used for various markets who didn't have an affiliate and were available on channels 251 and 253 (or something like that). I have only read of one person on here that actually paid the price of locals for an extended time for just the San Diego CW.
You can check a signal strength by hitting MENU, 6, 1 and 1 and enter the sat and spotbeam. I would look at a map of the spotbeam if I could find one because they seem to vary in the amount of area they cover. For example, I'm west of you by about 35 - 40 miles and get the Cincinatti locals with no problem. However, I couldn't get Knoxville or Birmingham if I wanted them (both of which are closer). Be advised (if you have AT100+ or higher) that it will change the regional sports channels you receive and if you have a sports package that your new "home" team will be blacked out. For example, I have Welcome Package (which doesn't affect the RSN issue as I don't get them) but I found that moving to Cincinatti helped as I am able to watch both of my local teams (Thrashers and Hawks) on NHL Center Ice and NBA League Pass. I miss the Pacers, Blackhawks (unfortunately) and Blues due to blackout because of the move. My guess is that you will not get Jacksonville locals all the way up here.