During this time of year we face a malady called cabin fever, because the lakes are all frozen over. However, I have been able to paddle every month for the last six years in central Iowa. Almost all winter long, except in extremely cold weather the Des Moines River is open below the dam of Red Rock Lake. The best access place is Howell Station below the dam, which has a small concrete boat ramp and parking area. One of the best parts of kayaking or canoeing here during the winter is the eagles! The eagles congregate here in the winter because the water is open and the stunned fish that come through the dam are an easy meal. On New Years day I paddled up to within 50 feet of two eagles perched on a log. The water levels in the river have always been good enough for paddling, and I've always been able to manage paddling back upstream to the ramp.
Pella has plenty of places to eat and stay the night. Most of the camping areas around Red Rock Lake are closed during the winter.
Route 163 to Pella, get off at the exit for lake Red Rock and follow the signs to the Dam. On the North side of the dam follow the signs to Howell Station.
Besides Howell Station you can go further down river and put in and take out at a number of places where there are bridges.