I sail the C22 almost every week here in English bay, Vancouver, Canada.
I have found the C22 to heel a lot more when I'm out by myself instead of with more people, so I reef in just about 11 knots of winds and it makes sailing a lot more comfortable. But then again, I'm a fairly light person.
With 3 people the boat can run under full canvas and heel almost 50% less up to a certain wind speed, I have found.
Also, about heaving to in the C22. This is from my experience....
Once the wind gets above 17-20 knots you will not be able to heave-to as well with the normal "back the jib" technique people often recommend. The bow will just move off the wind and you'll start making way and heeling over more.
If you're still making way, you are not heaving to, you're sailing.
Instead, reef the main and take the jib down or furl it in.
Then... release the main sheet until you have very little way on... (1 knot is good)
Lock the tiller to lee ward and tighten the main sheet in.
The boat should stay at a 45-50 degree angle off the wind and you'll be drifting at about 1 knot to leeward.
In stronger winds you do not need the backed jib especially with a light boat like the C22. The wind on the forward side of the hull should be enough (assuming your main is reefed down enough)
However, if you try to heave-to with too much way without the Jib, it's likely the boat might tack through the wind. Hence I recommend reducing speed before you do it this way.
If the boat continues to point into the wind too much, reef the main again if you have a second reef, or try unfurling some of the jib.
I strongly recommend "Storm Tactics" by Lynn and Larry Perry on more heave-to stuff, that book is price-less when it comes to heaving to in stronger winds.