Am a real Caron fan; they have quality and style but they are definitely VERY old-fashioned. Nothing wrong with that, but it's best to know what you are getting.
To me, Montaigne is rich and heavy and smells like very posh hairdressers used to, way back in the 1980s, or even earlier. Warm, powdery, 'feminine', syrupy sweet, musky, classy, elegant, complex, a touch of grandmother's handkerchief sachet ... overpowering if you don't like it. About as far from fresh air as possible, but, at this time of year, strangely comforting. Nothing cheap and nasty here.
I really like Nuit de Noel - it is indeed very suitable for the middle of winter. Incense, bitter Christmas spice, orange peel (NOT fruit), smoke, moss, maybe pine-needles (faint) or something dry and dark green like laurel or ivy, but also something floral and crisp and cool, at the same time. Probably my favourite Caron. To me, much more subtle than Montaigne.
I don't like Nocturnes - a matter of taste. A pleasant, light floral. Sandalwood, rose, vanilla, tuberose, soap - refined, ladylike; does nothing for me.
On the other hand, I DO like Caron's 'Miss Rocaille'. A real weirdo. Fresh, very green, grassy, perhaps the smell of of honey, plus an extraordinary extra note - some people say it's like plastic dustbin bags. I can see what they mean, but to me it also has a whiff of green banana; others say it smells of basil or even sea-water. I have absolutely no what is it - on me it does not last long, but the slightly bitter green flowers remain, very pleasantly.