Getting back to the original question, my only additional input is that theory and reality are in two totally different universes kind of like virtual vs reality. Each trip I take I learn to plan more for the unexpected. Enjoy next years trip MP. Maybe our theories can be discussed further at Canoe Copia while we wait for the reality of next year's trip to come to pass

WR

MP

I would base it on my walking time on a fairly level wooded (not Path) walk.
So at 2.69 miles that =  170438.4 inches.  My stride is 27 inches, divide that into the 170438.4 = 6312.5333 steps.  Now for the grade factor I would cut my stride by .33 ( less 8.91 inches) for grades 5% to 10% that would make my stride at 18.09 inches Any grade over 10%  I would cut it by .66 ( less 17.82 inches), that would be 9.18 inches per step.  At a 5-10% grade you’ll still be walking pretty much in a straight line. Over 10% going uphill or down I suspect you will be making much shorter steps or walking from side to side.  I figure my steps usually 1 per second so at a level grade it would take me about 1.7534815 hours to walk it.
Now take into account the grade changes from typo maps.  Figure the percentages of different grades and you should be pretty close.   This is a figure I use hiking in the Gorge and the only things that really throw it into a default are mud, water, pictures, and snack breaks.   Don’t take a camera or snacks and you’ve already cut that default by 50%.

qp

How long does it take to do a portage?

To figure it precisely, I check my watch when I step out of the canoe upon arrival at the portage.  I check my watch again when I paddle away from the other end. 

End Time - Start Time = Elapsed Time    It's over when it's over and not before.

Seriously, though, I just don't give it that much thought, especially on portages I've never travelled.  There's too many potential variables.

Mad_Mat's system seems like a good rule of thumb to me if you're goal is just to make sure you aren't planning your days too aggressively.

Yikes!  We just generally plan on doing 10-15 miles a day and if the winds are favorable and the portages easy we're done early and if not we're done late or we reconsider....

 This is very entertaining! I'm not sure you can "calculate" travel or paddle time other than in a very general way? Too many variables, at least in my experience.
 
Weight is a reasonable "doable", as well as physical conditioning for the trip. Efficient portaging techniques helps as well.

 I'm not sure planning using a "known" route that you use frequently will translate to the varying portage conditions you encounter on a trip?
 
Your body adapts to the load it's put under over time. it becomes more "efficient" at doing the same task repeatedly. Even a shorter route with lots of up/downs, boot sucking mud, or slick rocks will tire you faster than your longer familiar training route that doesn't feature those obstacles.

 I plan on "underestimating" my travel time, figuring you can always push on if your up too it and the conditions are favorable. I'd rather add a unexpected lake or layover day, than have to push hard to get out for a scheduled pick-up or depart time.

I go on what my body is telling me. I like an early start, before 7 am at least. I take a short lunch unless the winds are against me and then I might take a longer break and paddle later. Generally by 4 pm, I'm in campsite mode. I'll paddle later or take a hard portage late, especially if it puts me on a nice lake I have a layover day planned.

You can calculate/figure all you want, but we all know Murphy's Law will have a say in our best figured plans Worse case you go from Murphy's to FUBAR, in which case you call for the MARINES( JIMBO) on your little SPOT gizmo

I look forward too the day when I can travel when I feel like it, layover whenever I want, and come out when I run out of food.
 
Unfortunately in today's economy THAT day is getting pushed farther and farther down the road for me
 
I'm sure MP will get it all worked out too his satisfaction before his trip.
It will be interesting too read his trip report and see how close theory and reality are :question
 
Hopefully he won't be disappointed, and we'll be enlightened an/or amused