Blood furnace was a piece of cake.

I cleared it the first time - did have a shaman die due to bad positioning on the bosses AOE but after that I just ran and killed the first boss and reset.
I did do one final clearance so I didn't have any deaths. I was actually surprised to get through the waves of orcs with no mana issues, I thought I might struggle there, but it was fairly easy.

I went on to clear Slave pens the first time. The first boss was a real pain in the backside - I nearly fell asleep with the boredom. I got him down eventually, but should have setup macros to target specific totems to take them down quicker.

I did go to underbog and wiped a few times on the first boss. A couple of times were due to my misjuding aggro range in setting up and pulling the boss before being ready.
The other couple of times I just wasn't moving my casters and tank decently. I made the mistake of not having any ankhs on my shamans so had a long ghost run each time. Just cleared trash up to the first boss a few times then headed to Nagrand.

The team has been gaining rested XP, but next session I'll hit Mana tombs to see how they cope.