Saturday, Sunday and Monday will be very busy. Expect lengthy lines. This is always a very busy weekend for Disney. Signaling the start of the summer season for them. Although not as bad as the week between xmas & NyE.
A couple of suggestions:
Make a few PS before you arrive.
Have your group each make a top 5 list of attractions. Then if staying at a Disney resort use the extra hour option and focus on these list. Then anything else you get done after that is just great extras.
Also use a midday break. Believe me that is when the lines are the longest, the temperature the hotest and tempers the shortest. We go back for lunch, a swim or a nap. Then we return to the park before or just after dinner and stay for the later hours.
See you there