To add to what
@HereForTheT3a22 said, even with the precautions the parks have added, almost every single person I know who has gone to the parks since end of December (height of omicron) has caught covid very shortly after going to one of the parks. All have been double vaxxed and boosted, so thankfully they all had very light symptoms. Omicron has peaked and everything is going down again, but who knows what would pop up between now and March. I will say, my family masks up basically 100% of the time we're at the parks, unless we're truly well away from others or while eating, and we also don't eat indoors, and we've felt safe enough in the parks.
We went to Universal last weekend and it was insane. I didn't think it'd be quite as busy because it was a non-holiday weekend and it was FREEZING (Florida freezing, at least. In the lower 50s/upper 40s when we were there) and it was so packed we left after one ride. We're going to Epcot this coming Saturday and I'm expecting for it to be insane as well.
There's no less busy time anymore. You just have to plan around it being slammed from here on out.