The answer to your question depends on where you live, but in Western Washington where I garden in zone 7, covering an abutilon to keep it dry over the winter has worked for me. This is a tender perennial but I have found that keeping it dry over the winter forces it to go dormant. Then in late spring I cut back the dead wood and new growth emerges from green stems. Some years it takes the plants until August to bloom again but if we have a mild winter the abutilon may not die back to the ground and flower again in late June. I do suggest you check the covered plant every month or so to make sure no mold is growing and to see if a bit of water is needed. The soil should be very dry but not so dry that the plant withers up. Usually a cup of water once a month is enough to keep the roots alive. Good luck and Keep Growing, Marianne Binetti  P.S. Check out my Instagram and Facebook posting @MarianneBinetti and you will see photos of my abutilon and how I protect them in the winter.