A bit of a necro, but....
Have you thought of sending a couple of adventurers over there to scout the place out for you? Get them to join a guild, give them 50 gold for ship travel and boring services/mail delivery costs, then have them scout out a few regions every day or two.
It'd be a low-cost way of seeing if there's any weak points in hordes. How much do they move around? Etc.
They might even stumble onto an old item or two while investigating (it does happen sometimes).
Sure, they can't actually fight the monsters, but it'd be a cheap way of moderately accurate scouting. They're pretty expendable anyway. That way, we get all the information, while still being able to chop each other apart with proper armies in the meantime.
I'll have a new advy soon (enoblising my current for laughs), so I might be up for it, just to see how it goes. I wonder if the monsters ate all the undead over there? Could almost be a self sustaining scout if they didn't. Bring a tent and some adventure gear and see how it goes.
