On the south end, Wahweap has enough room for 4 to 6 simultaneous launches depending on spacing, with State-line nearby able to launch at least 3 or 4 comfortably, and Antelope Point will hopefully be open by then too... giving you another 5 or 6 boats in and out at the same time, plus the Antelope Point Executive launch ramp valet (they have a private ramp and launch your boat for you).
All together the ability to launch and retrieve as many as 20 boats at the same time is pretty cool. Up north you don't have as many choices so it may be a bit worse depending on time of day.
I know you asked about the north end, but I think overall the lake will definitely be busy if you're talking about the ramps and anywhere within 15-20 miles of the marina's.
The trick is to launch very very early, or wait until late morning (10-11am seems to always be pretty quick with no more than 15 minutes wait) and then head out somewhere a bit off the beaten path.
With wave runners you can carry a couple gas can's on your boat to refill and take them down the lake a ways, perhaps up Escalante. You'll find the closer you get to the middle of the lake the fewer and fewer people you'll come across, and the more beaches will be open.
The water will be chilly, but tolerable for the beefier folks in your crew, and the air temp will vary between mid 50's at night, and high 70's to mid 80's during the day.
The fishing or course, will be epic by that time, and hopefully the lake will have risen enough to submerge most of the whales people have been running aground on.
