Good strategy. I did that with my adopted kids. I told them details when they were too young to grasp it (3 yo and 4 yo). That way, when they really understood later, they wouldnt be as devastated. In between those two times, I didn't touch on it too much because I wanted them to feel secure that they had a mommy.

I did the same with Santa. Haha. I always told them Santa was NOT real and that Jesus IS real. But I happily explained that Santa is part of a really fun game we play at Christmas time. They still insisted on believing in him, but had no shock or loss when they understood. I didn't want them to think I was lying about Jesus being real, so I thought I better not lie about Santa. Haha.