Wow, I hope this reply isn't too late to help you Egapillar. Sorry!

There is an option to do segments. When you click the button to go into routing mode, look to the bottom left corner for the option to toggle from "normal" to "segment". Now select your route points as usual. When you run the calculations, you should get segment calculations in a small window in addition to your normal route calculations. I set it up so each segment represents a day of travel, and voila, I have my day by day calculations.

I find that the best way to see what can be done in a day is to count the number of portages and to some degree the length of the portages. In places like BWCA, Quetico, Algonquin and such, the distance on water is sort of secondary to the portage issue. In our experience, at least as senior citizens, once you get up to 4 or 5 portages for a day's paddling, it is time to see what kind of campsites are available. This rule of thumb might be different for you young hotshots.