Mooh, I believe the following applies to both Winfield and Santa Fe. This is, however, partly my impression and not necessarily exact.

Baby accomodations--bring your own.

Dogs--pets prohibited, but surely seeing-eye dogs would be allowed. Comfort--not quite sure what you're after, but I would say owner's responsibility.

Main Stage audience space--so far fine at Santa Fe, at Winfield gets jammed on Fri & Sat nights.

Parking--available, but probably not all of it terribly convenient.

The total Winfield experience incorporates camping there, I think that day-trippers largely miss out on half the fun. The campgrounds open a week before the festival proper. By festival time it's hard to find a campsite that's not a spot in an open field somewhat remote from the stage/concession areas.