Of the lakes mentioned the only one I have any experience with is Elsie. If you stay at the campground/motel the night before, it would be easier to get to the ramp at dawn. The weather is warm and so is the water, so why not make the most of the day? There will only be a handful of wake boats there before 6 and the ramp is huge. The boat traffic won't really pick up until around 7 but by 8 all the smooth water will be gone. By 10am it will be pretty busy at the ramp but there is a lot of parking.
Most weekends Sunday is always busier than Sat. but I don't know when/if they are doing fireworks or anything else at the stadium. That could change things. They used to launch the fireworks from a barge and so everywhere was a good seat at night. If it was me I would keep the boat at home for another weekend.