You don't even need a fan!
Ditch the dome and the fan.
I live in Nor. Cal., and though I currently grow all my plants in a greenhouse, at this point in the season I could even grow Highland Nepenthes outside without a problem (I live in a very humid area of Humboldt County). From what I've heard (and experienced), Northern California is one of the best places to grow carnivorous plants.
It's been one of dem days
The plants will do fine in low humidity. Just remember to let them adjust to it gradually or the leaves will get crisped from the sudden change.
How come chicken fingers are bigger than buffalo wings?
My Grow List