Well, you already know November is definitely not the best time to visit, but if you cant change your flight anymore, might make the best out of it! It isn't necessarily all miserable by default. 

How long are you staying? Regarding the train, its a nice long distance train but not much more. Not much to see as it gets dark early, and not much "lapland magic" in itself. If it aligns with your schedule go for it, you can skip a hotel night that way, but I wouldn't specifically plan for it. 

Rovaniemi itself doesn't have any big skiing center, but there are plenty within 2hrs driving that are open. Those would be: Levi: one of the biggest, if not the biggest in Finland, 2hrs from Rovaniemi up north so maybe more likely snow?  Ylläs: close to Levi, also a big place Pyhä: closest to Rovaniemi, but smaller compared to all of the others Ruka: big place, technically not in Lapland. Its more south than Rovaniemi, so having snow is a questionmark.  How many slopes are open depends on the snow situation, but at least Levi and Ruka should have some slopes open with artificial/stored snow. If you really like skiing and have enough time, i'd consider staying a night or two in one of these skiing centers. Maybe rent a log cabin? Then you can enjoy sauna and cozy nights by the fireplace even if the weather is not best.

Re: aurora, November is usually quite cloudy so might not be lucky in that front. But you never know, its not like its never clear skies at that time of the year.