GordonThree,
I had almost no issues with cable length. I replaced all the OEM outlets and added boxes except for the GFCI in the bathroom. It would have been a problem as it is on an outside wall and is a quasi surface mount item.
I did add an extra box in the kitchen because of cable length. I use it for a light in the cabinet.
I did have to "build up" one surface mount outlet in the bedroom because the other side of the wall is the shower.
I added an additional 20 amp and 15 amp shore power cords. My peak power use is 7000 watts. My continuous load does not exceed 80% of the total capacity.