Luther had his time on earth to do the same. When we get to heaven - those of us who are actual believers in Christ - we'll see.
Unfortunately, I won't be able to tell you unless you entrust yourself to Christ alone before your death. Guess if you don't, you could ask around down there...
but it will be on you, bro. Why don't you be sure today. Tomorrow is uncertain. Yesterday is gone. Scripture says that Today is the day of salvation. May it be yours.
And it's a shame that he lived it so unwisely.
Since you now, it seems to me, allow that Luther may not be in the kingdom after all, your theology is not completely dependent on him being saved.