This poster raises some very good points. I think it's actually in the Winter Games rules that any event must be snow or ice based.
There have been some superb 10,000 meter races in the Summer Games, and this has become a standard event in international competition. I love watching it and I'd hate to see it eliminated. One major consideration in considering a new event for Olympic competition is whether it presents a significantly different athletic test from another event already competed. The Olympics should not, for example, contest a mile when they already contest a 1,500.My first thought was to add a cross country race, but at some distance in the large gap between the 10,000 and the marathon, perhaps 13.1 miles. However, the problem here is that it would add an event that is not regularly contested outside the Olympics.
I love the idea of a cross country relay, perhaps 4X10 km. The leg distances of the two relays now contested are the same as an open event: ie. 100 and 400 meters, so I don't see this as a problem. Some might argue there would be little fan interest, but so what? Put the competition out in a park and let the fans attend free of charge. I am sure the cross country ski relay in the Winter Games is not as hot a ticket as hockey or figure skating,but it's a great athletic competition with ample participation by various nations, and nations from all over the world would send teams to contest a Summer Games cross country relay.