In a short-distance race, a dog team can reach speeds of 32-40 km/h.
The size of a dog team is not always the deciding factor. If a team of 4 works perfectly together, it can easily keep up with a team of 6.

On a "normal" dog sled trip through a flat landscape, depending on the snow conditions, you can manage 10-15 km in an hour. In deep snow, bad weather and when going uphill, you will of course make much less progress.

For comparison, here are a few figures that were determined in a race with mediocre trail conditions:

Team of 4 dogs: 13.51 mph
Team of 6 dogs: 20.49 mph
Team of 8 dogs: 20.44 mph