I used to be able to portage in two trips (20 years ago) but now it has become three trips.  I'd rather walk a little further and cut down on the overall weight for each trip.  Also agree with ST that safety is first and speed second so taking one's time is a smart thing to do.
I have several packs, in order to get them stashed in the kayak:  in the back: two tube shaped packs with the food, a small duffel with hatchet, saw, other cooking stuff, etc.  Then a small pack with stove and coffee fixings, a small insulated pack for cheese and fresh meats, and a 2 1/2 gallon bucket with lid with dishes, pots, pans and etc. inside it.  Where I sit is next.  In front of me is a medium sized Sealine rubber pack with all my clothes and personal items.  Under the front deck I have a wedge shaped pack with tent, fly, ground tarp, large rain tarp and the rope, poles and stakes.  In my lap or beside me a medium dry bag with roll top with all the stuff I need while I paddle, sun screen, camera, map, compass and a zillion other little things.  Strapped on the back deck a Sealine shoulder type rubber bag/pack with all the sleeping stuff: bag, air mat, book, pj's and more.  If it sounds stuffed to the brim, I assure you it is.  At portages the Sealines and the tent wedge pack are carried as is.  I have another Duluth style pack to put all the small packs I listed into and carry them like that, but then that pack is about all the weight I want to carry for one trip. (On one trip Kawishiway offered to carry that pack for me, half way across the portage he asked WHAT is in here!  I said, just about everything.  ;D)  At the end of the portage I have to repack the small stuff into the kayak again.  >:(  This is a particular pain when one is paddling across several little lakes with short portages in between them.  8-)