what is the available cargo loading area length and width in a 2017 Ford Expedition?

Plywood is 48" x 96". You should go on Fords website for dimensions. I have an Expedition and it could not hold something eight feet long but maybe the long wheel base ones will.

I would recommend going to your Ford Dealer with a tape measure. If you want to carry a lot of plywood a pickup would be the better choice.

http://www.ford.com/suvs/expedition/specifications/capacities/

The EL Version can hold a full 4x8 sheet of plywood, with both rows of rear seats folded down the cargo space is about 52 x 101 inches.

The standard length Expedition, you can't shut the hatch with a 4'x8' sheet. Misses by a few inches. The EL model though, plenty of space to shut the hatch. Glad I went with the longer model.