One way to prevent cold legs in a packraft while on cold water is to line the bottom of the raft with a sleeping pad.

Does anyone know if using a wetsuit will provide enough insulation to negate the need to use a sleeping pad?

Travis,

My experience is that an inflatable pad helps some, but not too much, in keeping legs from becoming uncomfortably cold. You'll still get wet on the underside of your lower body, just not be immersed an inch or so. A wetsuit does a much better job.

Richard