Hybrid vigor and temperature tolerance
I'm getting back into growing Nepenthes after taking a break for the better part of the decade. I'll be ordering my plants later in the week, and I've noticed that there is a much larger range of hybrids available, especially hybrids between highland species that were rare in cultivation until recently.
The temperature range I'm dealing with is not-quite-highland, not-quite-lowland. For most of the year, average day temp is 75f, night temp is 68f. Night temps are the same year-round, while day temps have a low of 70 in the dead of winter and a high of 85 in summer. I'm mainly planning on mainly growing hybrids between highland and lowland varieties, because they did well for me in "household" temps in the past.
With the variety of highland crosses available nowadays, I am tempted to try a few and see what happens. I have observed in the past that Nepenthes hybrids generally exhibit heterosis, or hybrid vigor, and can sometime thrive in conditions that neither parent could tolerate, but I realize this only goes so far. Out of the plants that I am planning on getting, N. spectabilis x aristolochioides, and N. spathulata x glabrata are the two "solid highland" crosses I will be trying.
I would love to hear peoples' experiences with highland hybrids in less-than-optimal temperature ranges. I can't recall any specific examples right now, but I have been surprised by a lot of highland hybrids that are growing successfully as lowlands or on windowsills for growers willing to experiment.
Hybrids are without a doubt much more vigorous and forgiving in sub-par environnments. The 2 crosses you've chosen may do alright in your conditions as long as you can maintain at least 70% humidity. Far better choices for the conditions you described would be plants involving maxima, truncata or ventricosa as one of the parents.
I have a lot of windowsill nepethes growing very well. Not all are hybrids though