Ok - so in the end I chickened out and brought whole, not broken, eggs. I just brought a few eggs and wrapped them in paper, left them in their carton, and tied it together. I was mindful of them and ate them the second morning, when they were a filling breakfast before my 5.6 km portage. (ugh!)
In the end, I learned not that eggs will last when broken into bags, but that when packed with care, can remain unbroken in a pack without too much worry. However, boiling them in a bag was something I will not do again - not very appetizing at all!
At any rate, the trip was good - we had mostly mild, clear weather, with a day of rain and a morning of brief snow flurries - but all in all, the 7 of us did just fine. One of our canoes got a hole in it when we tried to paddle through a suggested portage area that had whitewater and rocks. Hey- we figured the water was high enough, ok? But, unbelievably, we used duct tape to patch the canoe hole and it held fast for the next 2 days!! Red Green would be proud...
Thanks for your input. have a great day!