1) if its a new plant, it needs to acclimate in a high humidity environment, and since you seem to have the plant in the open air of the room (IE: not in a terrarium) it would be better to place it - pot and all - in a bag for several weeks to lessen transpiration stress. Do you have any idea what the relative humidity in the growing area is. Nepenthes are rainforest plants and experience consistently high humidity in their environment, and you should attempt to emulate that as best you can.
2) Nepenthes require variation in day-to-night temps: please engineer a way for night temps in the mid-fifties, and day temps in the seventies, or at least the high sixties. In my greenhouse, night temps drop to 55F and the daytime highs often reach 82F, even in the dead of winter. A fluctuation of fifteen to twenty-five degrees is essential to long term health.
3) do not sit Nepenthes pots in trays; you risk waterlogged soil which can easily lead to root rot, especially if temps are as low as you describe.
Your soil mix looks good, but you may want to let the media dry out a it between watering a, especially while I acclimate sand forms a root system. I'm not talking about DRY soil, but the top half much of soil should LOOK dry-ish before you water again.