If you have invis and dual shields (100 stealth is probably good enough too), it takes only a few minutes to get to the other side. Without invis, it's much more tedious because the hostile trees will slowly congregate around you.
I've seen people dig tunnels to pass parts of the AF before. I think you can definitely make one across the bottom row. Don't remember about the top. Definitely not the sides.
Hoping to win with every class, doomed. Archer, Barbarian, Bard, Beastfighter, Druid, Elementalist, Farmer, Fighter, Monk, and ULE Priest down.