You already have some great ideas there Toffi, and I'm glad you will be staying with family.
I have spent lots of time by the bedside of my parents and husband in hospitals. You'll find that it will be the most physically and mentally tiring hours you'll ever live. Physical labor is a picnic by comparison as worry sucks out your core.
My best advice is to leave word with the nurse you'll be in the cafeteria if you're needed, and take your meals there.
Read a book while you eat, and take in a little fresh air before you return to your job. My very best wishes and prayers are with you and your Dad.
Life is not measured by the number of breaths we take, but rather by the moments that take our breath away.