You can coat the chicken and chill until ready to use later.
Use only balsamic vinegar. Other vinegars do not hold up to the recipe and will make the chicken taste briny.
You can add more balsamic to the recipe. I always add a little extra for even more sauce.
This recipe freezes beautifully. Cool completely after cooking and place everything in a zip tight freezer bag. Write the date on the bag. Thaw overnight in the fridge and heat at 350 in a baking dish, covered for 30 minutes.