Hi Rowly;
Sorry to be so late in replying, I have not been on the site much lately. Regarding Chinese and Africans, I did raise a pair of each this year and I don't know what to think of the results! The first thing I would caution you about is the pronounced nob they develop at the top of their beak. I am told that it is subject to frostbite in cold conditions and I guess you qualify for that definition. In our case we don't have prolonged cold temps and they have adapted nicely to a house I built for them. They are very good looking birds and VERY protective of their turf. They don't appear to be afraid of anything and they should be - I lost my Chinese Hen to a racoon. I now pen them every night. I guess I would do it over again, but I do find the Geese require a bit more maintenance than the ducks, but I anticipate that they will be good weeders in the garden in the spring. My African Gander weighs in at about 25 lbs - a very impressive critter indeed. My Chinese Gander is "only" about 15 lbs. I guess it's worth a try, have fun.
Jim