Nobunaga and Hideyoshi are both 13 chapters, so I would assume Ieyasu is as well. (Not done with it myself yet either) 1st chapters has 3 quests, 2nd to 6th have 4 quests each and 7 to 13 have 5 quests each.
Stamina cost seems to be +6 of the chapter number, aside from the very first mission, which is 6. So for example, every chapter 11 quest will be 17 stamina each. There's some chapters noted as 1/2 cost which is only suppose to show when you're under Lv15 and appears to be a bug as it does not apply the 1/2 cost.
So clearing an entire story requires 780 stamina + 13 more stamina for 1 time, 1 stamina cost bonus stages after completing the last stage of each chapter. Totals up to about 40 hours worth of regular stamina regen. So 5 days at the minimal of regen to clear all 3 if you do nothing but run them and clear them on the first attempt. Should be faster if you factor in stamina refilling from leveling and first 15 levels being 1/2 off if you're still under 15.
Question is whether or not your party can handle the stages, they're not exactly hard but you can still wipe if under level and/or using the wrong party set up. But you should have 4~5 extra days to level if you need to.