I say go with maps, it will give use another bargaining chip faster than the other choices and give us the ability to move by water.
I believe that GS Squad should press north for a couple of reasons. To steal from Master Sun (Sun-Tzu), to attack the TNT city there moves our fast troops into intractable, enclosed ground which would be fine if our units were restricted to one movement point but since we are twice as mobile as the Immortal we should take advantage of that and move north into the open, light ground before swinging west and burning some cities.
Also human psychology makes it a better decision to go north. Also we do not want to lose our mobility, (I'll state the stats in case there are any out there that like me have played Civ4 too much and forgot them) a Mounted Warrior is 3/1/2 compared to the Immortal's 4/2/1; we can NOT go toe to toe with an Immortal unless we have the mobility to retreat and I don't mean withdraw chance in a battle, but the ability to run away to spaces for every one they take, they plains in the north are much better for us.
I assume that TNT has some where between 7 and 11 Immortals left, five are in the Jungle between us and TNT the other are either in the Jungle also or in the Cities closest to us, I can say this with such certainty because like all humans defense of home (or in this case Empire) is a priority. I may be misremembering but I recall one of our units stumbling across a couple of undefended TNT cities a few turns ago, they will not make the same mistake twice and will concentrate units in the cities that they believe to be most likely to be attacked, those cities closest to us, and they've had a couple of turn to move units in since they saw us.
I believe that the GS Squad should act as a harassment force, it should only attack lightly defended cities and raze them plus cut road between TNT cities to slow the movements of TNT troops, and if at all possible to get the TNT army to chase GS Squad. I would even suggest our External Consul Nobody to send inflammatory messages to TNT to get them to focus on destroying GS Squad, the more tunnel vision the better, if we were to get them to move units along the roads we have cut to protect the cities closer to the GS squad we can get those units out of position for when our CR Squad comes out of the setting sun to collect on past debts. Just my 2 cents, I could be completely wrong on how they have set up.
Also Robbi could you please put up a screen shot like the one on the first post in this thread that shows much of the continent.
-the Wolf