Do I stand a chance applying to level 3 NICUs with only 6 months - 1 year of level 2 NICU experience?

Absolutely! Depending on wht you experienced in your level 2 unit, you may have the basics already and understanding of the neonate transitioning from womb to air. I will add that you don't want to appear job hopping, and make sure you give 4 weeks notice before moving on. Good luck!

I had a few years of Medical Surgical, ICU and OB before I applied for a Level 3 NICU position.
I was oriented a month on day shift and then a month on night shift to prove I was good for them.
It was tough. And that was in 1985. Today, with a nursing shortage in many areas you may get into the position. Again, a good orientation in a hospital system should help. Best of luck.
Level 3 NICU is tough, scary but very rewarding.