What to do in the cold winter months? Here's a few ideas:

Enjoy the not-so-crowded Amsterdam streets. It is possible to maintain a decent pace, but only until mid-April.

Cycle through the Vondelpark and get an idea of what it looks like without 10,000 people inhabiting its grounds. Biking keeps you warm, too.

Count the number of Dutch holidays approaching in the next few months. I guarantee you'll lose track and have to start over.