Well, my needs are very different than yours. I'm a cord-cutter, but with a full streaming TV package. I need ESPN and HBO (which I get for free) and other channels, and also the networks, since I only get half the local channels without constantly moving the antenna. Unfortunately I'll have to give up my longtime heavily discounted Directv Stream service for Hulu or YouTube to get NBC Philly. I won't rule out Comcast either, at least not while there's an introductory rate.
But none of that helps me for the next three months! Actually my best play might be to get a PA billing address now and just make the change to my service. At least based on my current experience that, not actual location, determines the channel package (i.e. when I'm visiting family in PA I am still watching the Portland regional sports network on my cord-cutter service. Whereas MLB.TV also uses IP addresses. Which I guess suggests another possibility, lol).
And MLB doesn't really have much control over this stuff. It is dictated by the huge boatloads of money they get from Comcast (as well as Fox etc.) until those contracts (or the companies willingness to pay for that level of control) run their course. Half the reason they paid the Phillies for those rights is to try and force people like you and I to subscribe (much more than simply viewership and advertising). And the cord-cutting/lack of a la carte is an industry-wide problem (i.e. we could just as easily say that Fox News or the Cartoon Network or ESPN doesn't understand what cord-cutting is all about).