I'm more a fan of CPs that don't need to be pampered (i.e., ones I can just put outside and forget about aside from watering), so I've never had any Nepenthes before. My sister bought two plants a couple months ago, but then had to travel for work and is going to be gone until sometime next year, so it's up to me to keep them alive until then. The big one is N. alata and the small one is N. x 'Gothica'.
At first I had them in my bathroom thinking that the limited light and higher humidity would be good for them, but they started not looking too hot when the pitchers started shriveling and the small plant got some black spots on its leaves. I then moved them outside onto the deck with variable humidity and direct sunlight for a few hours in the morning (and bright indirect light after that), and they seem to look better. The large plant has developed a purple hue on some of its leaves as a response to the increased light - I think that's a good thing?
I know these are highland species, so they've been enjoying the cool, rainy weather we've been having the last several days. However, when I put them outside, it was pretty hot with temperatures near 90 and low humidity, and they seem to have handled that fine. Basically, I want to keep them outside as much as possible since they seem happier out there (like most plants, I've found). What conditions would require me to bring them inside? I'm on the border of USDA zones 9b and 10a, so we usually only get a few light frosts a year.
I was planning on bringing the plants inside overnight when temperatures drop below 40 (though I've read they can tolerate slightly lower than that), and bring them in if temperatures get above 90. Does that sound like a good plan or a recipe for disaster?