New York Columbus day parade

I have ta few questions, I apprecaite any help for a tourist:

  1. what happens if it rains? do they have it anyway or postpone it?

  2. sitting in the Grandstand, is there a cost to sit in the Grandstand or is is like the Thankgiving parade where you have to arrive hours early to get a seat? How early should I arrive

  3. should I bring food with me? Parade is from 11am to 3pm

another alternative, if I bought a cheap portable chair can I sit close enough to be ble to see without people in front of me? If I take a potty break will someone steal my chair?

I have a bad back and can’t really stand for the 4 plus hours of the parade without being able to sit periodically.