We had a group of 14 people camp in the dispersed camping area off of Hohnholz Lakes Rd overlooking the lake. Really great spot, plenty of fire rings, tent spots, and some nice log benches. I would recommend bringing your own firewood for the dispersed area, unless you have an axe or chainsaw. They also sell firewood at the regular camp grounds.
The lake make for some good swimming during the day, there's a nice beach spot on the Northeast side of the lake, just drive a little farther down Hohnholz.
Note that no one in our group had cell phone service for most of the drive up the Poudre Canyon, as well as at the camp sites.