I did the Pennine Way three years ago (or was it four?) North to South. Did the first stage in one go, a bit long but as long as you have water, should not be a problem. Fairly easy going, my memory is that there is no Lake District type mountains to worry about, just a couple of steepish hills to slog up and over. I did it over 14 days I think, carried my rucksack and tented (easy to find sites) on all but two nights. Mind you, I did have good weather. I have just recently hiked from Keld to Edale, camping over 7 nights and noticed it hasn't changed much. The section that always annoys me most is that when approaching Edale from the north, the last mile is uphill! I am 70 in April so if you are not burdened with ill health and poor quality feet, ankles and knees just go for it!