To tell you the truth, I have no idea how fast lowii X campy grows because I just got it today as a cutting... from what I can see it does grow pretty fast because this cutting is about 3 feet across and is just about to start making uppers. Yes, they are true intermediates so they should LOVE your conditions.
I still have the greenhouse but Highlanders have really been my interest since they are so cool... there are a few interesting lowlanders, but to me every highlander is interesting in some way (which is why my HL chamber is so packed!). Also, the plants in the GH are in recovery now from "who knows what" and since there aren't as many plants in there there isn't a lot of updates to make for it. I will be getting some cool raffelsianas and what not in the future, but for now I just gotta get the plants back to health before I go to work at a Tissue Culture DNA lab to hopefully learn to TC rare Nepenthes seeds.