In all honesty I think at that time scale it may be more practical to create a lifeform that does not depend on oxygen or water, and only needs sunlight for ene

In all honesty I think at that time scale it may be more practical to create a lifeform that does not depend on oxygen or water, and only needs sunlight for energy. It may have to be silicon based, and I use the word "lifeform" in a very liberal sense.