Is the admission only for single entry or can you leave and return in the same day? Curious if you can re-enter same day.

I believe that as long as you have the wristband on your same day admission will allow exit and re entry

Yes you can, we left for about an hour to eat and we came back in. They will give you some paper bracelets you will show this to enter again.

Grab a wrist band and you can come and go in the same day

Yes, you can come and go back on the same day - as long as you have that days wristband. If you are going to go more than twice a year, you might consider buying an annual membership.