Q: Given a travel related situation, and given a specific question about the situation, summarize the question into a title
I'm going to visit Amsterdam next week for a couple of days and then I'd like to take a series of bus and/or sea trips ending up in Warsaw, or anywhere on the east shore of the Baltic Sea (from Gdansk to St. Petersburg). I'm yet to decide the details of this trip, whether it will be so distant or not, but I would like to know the following:

When arriving at a reasonably large town in the Netherlands, Germany, Denmark or Poland how likely am I to find cheap overnight accommodation without prior booking?

The idea is to arrive to a town, go sightseeing, have my six hours of sleep and then move on to the next town. But the plan isn't going to work if I have to spend most of the time finding a bed and shower instead of enjoying the sights.

So, are such services common in Western Europe?

A:
Finding overnight accommodation in Northwest Europe