Smoking Brisket

I am smoking brisket tomorrow for my family and it's my first time. I have a brinkman vertical water smoker. The brisket is 13 pounds but I had to cut it into two pieces, both about equal, to fit it in the smoker. Couple questions...

1. Does cutting the brisket in two change the amount of time needed to smoke? Or would it still be one hour to one and half hours for 13 pounds? So 13 to 19 hours? I plan on monitoring the internal temperature with an electic thermometer to get to 180 degrees.
2. I don't really have 13 to 19 hours so any suggestions or should I just make that amount of time?
3. Should I wrap the brisket in foil after 4 or 5 hours or will I be fine with moistness if I baste and keep the water full?

I really appreciate any help. Trying to impress the whole family!