We will be in Amsterdam for five days in November. Apparently one of the days is when Sinterklaas comes. I am wondering how this impacts getting around town that day. It sounds like a big deal. Will there be massive crowds in the city that day? Will normal sightseeing be possible and does it last the whole day and evening?
I'm not living in Amsterdam, so I have no first-hand experience, but I've never heard of any interference with normal life because of the Sinterklaas parade. Buses and trams crossing that route will, of course, be disrupted, but otherwise I can't imagine it will of any influence on your plans. It might be fun though to have a quick look at the parade. After all, Sinterklaas is the most loved festival in the Netherlands. For more information: www.sintinamsterdam.nl/overige-informatie/english/
(The depiction of Sinterklaas' assistants - Black Petes - has become the subject of a heated discussion. Some finding it demeaning for people of African descent, others an integral part of a Dutch tradition. In the years to come he will change into a less black figure.)
It's not like the Macy's Thanksgiving Day Parade - it may take a little longer, but you'll be able to get around. Some transit may get re-routed, but Amsterdam is very compact and as long as you don't have any mobility issues, you should be able to get where you want to go.
In the meantime, the absolute best description of the cultural differences between Santa and Sinterklaas can be found on YouTube by searching for "David Sedaris Six to Eight Black Men".