So the final target will be between Trenton and Princeton, although -- depending on other factors -- we might only tow as far as some convenient place on the PA side of the Delaware with easy access to 95 or US1. Since our destination is that far south, I've figured to this point that swinging up and around on I78 probably couldn't do much for us, especially since we'll be looking to stay on controlled access roads as much as possible.
Google's algorithms don't have a particularly strong view of the route to take in any case (I can actually move the destination 10 feet and get sent through DC and Baltimore rather than PA at all). At the moment, around Philadelphia we're looking at 76 to 276 to either 95 (the western route around Trenton) or US1.