Chris,
Algonquin park is a series of lakes joined by small rivers that feed into and out of them. In many places you have to portage the canoes and gear to get into another lake or around rocky places in the rivers.
There was nothing that prevented us from returning to the base camp early. We thought of sending two guys back for food but that would have ment staying put for a day so they could catch up. As it was we got to a decent sized island in one of the lakes and we stayed there two nights anyway to fish and rest. Besides it was a really cool place to camp. This limited our total travel to about 80 km. A typical conoe trip there with people who are used to it and well fed can easily double that in a week.
The other group actually threw food away aftert the second day because they couldn't finish the meals. The real kicker is that we actually passed them in camp on the third day and just waved!! God has a sense of humor. Mac