Again, I have lived outside of Buffalo in the burbs and the lake effect snow is mostly Hamburg,Orchard Park.etc..
I wouldn't per se go on the Maid of the Mist at that time of the year...but if the weather isn't too bad you can walk around for a few minutes! *and we all see forecasts for the week--so play it by ear........If there is inclement weather then go somewhere indoors. BUffalo is still a fun place to visit!!

To find out if the activities you'd be interested in doing will be open, check the official websites:

www.niagaraparks.com (Canadian side)
http://www.niagarafallsstatepark.com/ (American side)

The Canadian side lists Maid of the Mist open to October 24th. The American side lists it (and Cave of the Winds) as seasonal - probably the same time. Journey Behind the Falls is open year round as well as the Butterfly Conservatory. The Whirlpool Aero Car is open to November 25th.

So, there are definitely things you can do in November, but not Maid of the Mist. And, of course, you'll still be able to just watch the falls as much as you want.