Yeah, no NESN in that scenario. Much of this thread is dedicated to finding ways to get the Sox broadcasts (but even then you're just getting games, not pre-, post- or stuff like Charlie Moore. The pity). If you're outside the Sox broadcast territory, it's easy; just get MLB.tv which works on an AppleTV, a Roku or over the computer (like the other services you mention). Inside the Boston territory - most of New England - you'd need to get creative because Sox games will be blacked out on MLB.tv - they check your geographic location by IP address. One idea is to use a proxy service to make your IP appear to be from outside the region; another is to find a TV subscriber with the Extra Innings package in another place and arrange to locate a Slingbox on their cable TV setup. There may be additional ideas I'm not fully versed on - a few in this thread will know more.
And of course there's the radio.