Hey! Thanks for reaching out! for online, I recommend rolling a d20 each time you'd pull a block, noting the number each time. If you roll the same number 3 times, count that as the tower falling. Unfortunately I don't know where you'd find an online tarot deck to pull cards from
I consider the tower falling the end of the game, but if you wanted to, you could restack it. I'm not the boss of you. :D