On a canal boat holiday, you can cruise anytime between dusk and dawn. Although theoretically in the height of summer, you can get up to 16 hours of daylight most hirers will travel between 4 and 9 hours per day, at an average speed of 2.5mph. If you travel for 7 hours per day you might for example cover 17.5 miles, but remember that's assuming an obstacle-free cruise, in reality you'll likely have locks and movable bridges to tackle which will take more time.
You can use our canal route planner to get a more accurate idea of how long a route will take including the time taken to tackle locks and swing bridges. Over a week a 100-mile route will be a fairly active route and is at the upper end of how far most hirers would like to travel.