Hi James, we spoke briefly at the Norwood clinic.
You can do either, it just depends on the amount of time you have, whether or not you will need to drive your car before finishing, etc.
Polishing the whole car, and then coming back around and sealing the whole car, will save you a lot of time compared to if you polish and seal one panel at a time (swapping pads back and forth can get time consuming).
However, if you don't have a lot of time to work and need to split the job up over a few days (as you've said), then you can certainly polish then seal one panel at a time. Like I said this will be more time consuming. I had to do my G8 this way because doing the whole car in one sitting was unrealistic for me. Also I don't have a garage for it so I didn't want to polish the whole car and let it sit outside overnight with no wax.
So either way works, it's just a matter of what works best for your time.