It's really impossible to predict what crowds will look like later in the year when we don't even know if there will be crowds... at all. Even if the parks are open, we don't know if they will be open to full capacity or what kind of cuts will need to be done -- a half empty park running with half staff is going to feel just as busy as a full park running with full staff. Personally, I would favor going later if I were picking right now. For one, you're almost guaranteed to be safer since we are not terribly likely to have a vaccine by November but are fairly likely to have one by next November (though anything's possible). For two, I'm generally more than happy to let someone else be the guinea pig on these sorts of things. Trying to ride a ride the week it comes out is always going to be more miserable than trying to ride it a year later. For all the people who are desperate to be in the parks as absolutely soon as they open, there's also going to be a lot of enraged posts and complaints at City Hall when they do.