The game of ToA i'veI've been playing in has been going for 7seven months (One 5-6 hour session per week) since I joined, and the rest of the party was around level 5 at that point - we are now up to lvlevel 10.
So far, we had one full party wipe and one where only two of our 5 survived.
We entered the last dungeon of the campaign about three sessions ago, but our gm told us that we are still less than a third through said dungeon, so probably around another 10 - 13 more hours to go ( based on our current speed).