I would count on time travel with some certainty. How is God able to prophesy and predict the future not just hundreds of years but millennium with accuracy? God is not boxed in by time or space or science, He is the Author of it. Time will have no meaning in Heaven once the judgement is executed.
You are getting into an area that becomes .. What can GOD do that Man can never do then.
I also know that there are some things that GOD cannot do.