Matt, could you do the mountain in the back corner by the 9-v controllers? It would need to be a smaller footprint than what you had at Greenberg but perhaps you could go for height rather than width.
That’s basically what I was thinking, assuming I do it at all. Smaller is better, for sure. Josh may need his gray 15″ baseplates back, anyway, so I could convert to green plates and work with that. Biggest concern is the trains’ turning footprints – as we learned this weekend, the Maersk and Polar Express actually swing wider to the inside (due to long wheelbases) than the Horizon Express. So, perhaps we can do six baseplates, in a 3-2-1 formation (see image), such that it covers that bottom left corner but is big enough to have at least 1 straight track on either end of the curve and the trains can thus enter/exit the tunnel without incident?
One other thing is I don’t know if we have enough track, even between the two of us. I contacted a guy on Bricklink that is willing to sell me 72 lengths of straight track for $300, but I don’t have the money at the moment (Christmas coming and all).
I’m assuming it’s 9V track, not the kind you’d need to modify? I could be convinced to chip in for that purchase – that’s a good price, eh? ~$4.20 / pc?