We did a full day. It doesn't open till 10am. By the time we went on all the rides, did the muddy puddles thing, lunch and meeting the characters etc, it was almost 4pm. DD naps every day at home but can get through the day without a nap if we're out. As soon as she was put in her car seat she fell asleep! Normally we have to drive for at least a minute or so! We might do the two day pass next time (second day free if you book a hotel through them).
We just stayed in the nearby Holiday Inn Express. Only because it was free (DH sometimes stays with them when he's away for work so has a loyalty card). Basic but we only needed a room and it had everything we needed. There were horses at the front which pleased DD. We spent a few hundred in total but it was worth it to see DD so happy.