It may be immodest, but I think the Serious Casual Story may be part of the answer you're looking for.
Serious Casual: What the hell happened here - Elitist Jerks
I think there's still time for a reroll guild to finish the game. With hardcore 10-man farming, you can gear up well enough to jump straight into Tier 6. There are plenty of logistical issues with reroll guilds, but is it possible - yes.