Okay, guys, thanks for the comments. It's a quandary. I normally like to thoroughly scout an area, rather than stopping 1 tile short of marble or whatever, but in this case, I think if we're going to commit ourselves to a REX strategy, then we're most concerned with southern expansion. Our next border expansion will only expose one more layer of tiles. Probably not enough and anyway too late, imo. Moving the scout SE immediately corresponds to my original plan (but I was hoping to make it to the west coast without getting stuck in the woods) and will get him to that lush-looking site south of the mountains by the time the worker is done. Then we can decide if we want a warrior to protect a roading worker, or another worker, or the settler immediately.
It also may help us decide whether there's something better to research next than The Wheel, my current first choice.
Also strikes me as a bit of a waste of our scout's 2 movements, snowshoeing through this hilly, woodsy, arctic tundra. A warrior can do it just as quickly. I'd also like to get the scout out of the woods before any bears spawn, although there'll be panthers down in the jungle. A scout often has a limited window of opportunity to explore. We need to make the most of it.
So contrary to my normal style and some of your wishes, I've decided to scout due SE next. I don't even want to risk going S-SE because I might lose another turn trudging through woods. Plank me it turns out to be a blunder...
Continuing...
Agri researched, marble located, plus some cattle, grapevines, and lots of crappy land. Time to decide on next research. I vote for The Wheel, which will speed up our REX more than other other single tech, imo.