Our minister used Hitler as an example, and asked what if Hitler had asked for forgiveness before his final moments and God granted it?
I don't think Hitler asked for forgiveness. If we can believe him then he thought he was doing God's will. A person would hardly need to ask God's forgiveness for that. If Hitler believed in God then he probably thought he had a special seat reserved for him at the right hand of God.
In answer to your question. If there is a heaven and Hitler is there, would I be upset? Hell yes! But I wouldn't send Hitler to hell either. Torture is inhumane. I wouldn't wish that on anyone. People like Hitler should never have been born in the first place. But since he was, he should have been annihilated which actually is what happened to him. Unfortunately that is what happens to everyone.