My cagoules are large and fit over anything, summer and winter, and they fit just about anyone (at least someone who doesn't care about wearing oversized clothes). Being large they vent well, but may need to be tamed a bit in high winds. I almost always use them with the bottoms folded up, rarely did I ever unsnap the bottom part, maybe in heavy rain once or twice. I generally skipped bringing rain pants. They were easy to make, too. Mine have one big kangaroo pocket in front, perfect for throwing in your hat or gloves.
One downside is I was once rapelling down a vertical face in the winter with a cagoule on and it began to get sucked into the rapelling device. I quickly stopped and got it unjammed, but had I gone a few feet further I might have become immobilized by the taught fabric, unable to do anything about it, perhaps becoming unable to breathe! Lesson: be careful about what you wear when rapelling, and be sure nothing can get sucked in.