I'm not familiar with either of your plant care requirements, but I have a few that need winter rest and I also do windowsill growing. If they require bright light...I would do the kitchen place you mentioned. I would opt for the light more than the temp drop. Most orchids will adapt to temps, but will not bloom if not enough light. That's been my thinking, anyway. I'm definitely not an expert grower by any means, but I too have a challenge with winters, lighting, and humidity issues.
