Looked at the current node network on BDFoundry maps, did some math, and came up with the low CP map for the upcoming Mediah Patch. Only costs 67 CP to connect all the current towns and the new, expected towns.
Two things below: first one goes to the GDoc with the work and right below is the actual map with the node list (it's a large image--approx 3800 x 2300 pixels large). Hardest part was splicing together the map.