Purgatory And The End Of The World

[AveMariaPurissima]

I've been wondering about this for a while, and wondered if someone could clear this up for me.
My understanding is this:
After Christ's 2nd coming, purgatory will cease to exist. So if this is correct, does this mean that everyone who is alive at the time of the 2nd coming will fall into one of two categories: either being perfectly purified from sin and ready for Heaven OR in a state of mortal sin? (i.e., is there not going to be anyone who is in the state of grace but still has venial sins and/or temporal punishment on their soul?)

[cappie]

What will happen to those people who are alive at the time of Our Lord's coming who are in the state of venial sin? Most likely, they will have to undergo tribulations and sufferings in the flesh before the immediate coming of Our Lord. For, we are instructed through the Creed "He shall come to judge the living and the dead."