Issues:
- How do you recreate the energy that you immersed yourself in when you made the smaller painting?
 - How do you not "generalize" what you've already recorded?
 - How to you keep areas of seeming-emptiness, which will become only larger and more intimidating, interesting?
 - How do you avoid losing interest in what you're doing?
 
Advantages:
- You have the opportunity to improve your vision -- improve composition, improve color use, improve focus.
 - You also have the opportunity to REVISE your vision.
 - You can fine-tune your skills over days, weeks and months without worrying about the light changing in two hours.
 
All this bears exploring.