When you outlast your opponants in a 45+ minute game

The only thing I could imagine would be to run out of minions when you don't clear them and stack them up instead. There is always a highest number in code (they can't count until infinity) so someday, probably 20 hours into the game and 10000000000000000000 minionwaves later, there will either:

1. No minions spawn anymore
2. The first minionwave will dissolve
3. Your game will break

Probably 3