Did I get the orientation correct on your picture?
Based on my experience up at my brother's place, a gravel driveway will help a lot vs tracking mud all over the place.
If the box fan comes with it, make an opening for it and use it to ventilate the place. Or just stick it up in the rafters near the vents at the top of the walls.
You need to convince your wife that house projects will be a lot easier if the shop is setup first. Trying to get things done while 'making do' out there will only slow progress down in the long run.