We visited Rambouillet in the summer of 2015, and it was a mixed bag. The chateau was under construction, and we were only able to visit a very small portion of the building. We were with our French friends, who had made the reservations, and we thought we were going to have an English tour (when you reserve, you can specify, and you do need to have an accompanied tour). It was ridiculous for our family, with one fluent French speaker, one "intermediate level" speaker (me), and three who spoke no French. Our friends tried to quickly and quietly translate at the back of the group, but the guide was speaking so rapidly that we only got bits and pieces of info. When he was asked to please slow down by my French friend, he nodded curtly and continued on at the same "grande vitesse" We looked at each other, laughed, and gave up. The brochure we received with the tour gave minimal info about the rooms we saw.
We toured the grounds on our own that day, and while it was great to be with our friends, the experience was just okay. Small, pretty gardens, scenic waterways, a deserted farm setting...Perhaps you'd have a better experience on a guided tour of the grounds - or not?
We also visited Rambouillet in February a few years earlier, and just drove around the grounds, imagining the summer scene. I wonder if you'd feel it was worth your time in November.
If you haven't explored Chartres in your previous visits, perhaps that would be a good day trip for you?
Laurie