If you love animals, go to Kenya or Tanzania. I've not been to Kenya, but Tanzania was pretty wonderful (although not on your initial list). You can do a safari (pricey but there are cheaper options). Although I enjoyed it, two days of that was enough for me because it's all sitting. We also did a four-day trek WALKING THROUGH ZEBRAS. How cool is that? There are volcanoes to climb. There's also Mount Kilimanjaro. Food was nothing spectacular, though.
For food and outdoors, walking and hiking tours in Italy, Spain, or France would be great. We've been to all but only a walking tour in Spain, southern Spain to be specific. No walking tours but I have gone hiking in northern Italy in the Dolomites and some walks in southern France. I don't know about in December, though. Those would likely be better in the spring or fall.
Two years ago we did a Scandinavian trip during Christmas, which was fabulous. We spent a few days in Copenhagen to take in the sights, drink their Christmas beers, and visit their Christmas markets. We did a short trip to Sweden to visit people, and then we went to Finland. We spent two wonderful days in Helsinki just enjoying the Christmas spirit and then went far north where we saw the northern lights. We also went snowmobiling and dog sledding and all other sorts of winter wonderland things. This was also a pretty expensive trip. Also, I live somewhere hot, so for me cold and snow are a treat. That may not be the case for you.
I visited a few countries in SE Asia a long time ago and it was in spring. I was in Cambodia last winter. The weather was perfect. Angkor Wat is amazing. You can rent a bike and ride all over it from the town for a few days. There's a lot of history in the country, too, some of it very sad. We rented bikes in Thailand and did something similar a long time ago, visiting lot and lots of ruins. We also rented a motorcycle and went up into the mountains, where we did some hiking.
I'm sorry. I can see that I am not going to be any help because I could just keep going on. But if you narrow it down and have specific questions, I may be able to help.