Make sure to check the EE schedule, I think it may change sometimes on holidays. Ordinarily, Thursday is EE at MK, Friday is AK & Saturday is MGM. If you're staying on-site and your toddler is an early riser (like mine were), then try to take advantage of EE. If you're off-site, I would recommend going to a different park those days but getting there when they open. We always had the best luck by getting in early, doing as much as we could until either it gets really crowded or until lunch time (whichever comes first), then we would go back to our room for naps and return to the parks in the late afternoon/early evening.
It's going to be very crowded at all the parks when you're there, so you'll be best suited to think ahead and prioritize the things you really want to see. There are sample touring plans in the Unofficial Guide for families with small children that can help you in this regard.
The best advice I can give based on our own experience is to plan plenty of down time and take cues from your kid. All of the parks can tire a toddler out even if you are only pushing them around in a stroller because of all of the visual stimulation. There are lots of other tricks that maximize your time at the margin - eat a light breakfast in your room as opposed to a big breakfast in one of the parks, learn how to use the FastPass, be familiar with the layout of each park, just to name a few. But I believe one of the biggest things is to develop a plan and make sure everyone in your party understands it and buys into it.