dmar... Ive done the tourdelakes several times. It will thin out quickly. You might have a group if you stick with one, and there are a couple of pretty stalwart hills in there, but nothing IMPOSSIBLE. They will be short and severe if anything. Plus... its not as if the lakes are all sightseeing anyway... you go through lakewood.... meh... and then hit blue springs lake, etc... nothing extraordinary and honestly much of the ride is far enough away from the water, I think your fears about sightsee-erz is pretty much unwarranted.
I would think the longest hill would be about Highgrove size or so, and the steepest pitches will be around Blue Springs lake. Up to you brotha.