I've been flying my DG800A with Rotax 505 in the cold weather of central PA recently and have the following recommendations. 1. Bundle up, rigging in the cold can be brutal. 2. Expect the batteries to lose charge more quickly, and for the engine extension/retraction to go a little more slowly than normal. 3. If CHT is below 0 Celsius before cranking, use the choke to start more reliably. 4. Read your aircraft manual regarding cold weather operation; some gelcoats may crack in extreme low temperatures. 6. If there is precipitation, make sure to check all your static ports/leading edges for snow and ice accumulation.