When should I change to pot of my snake plant?

Snake plants are very hardy. The only way it can be killed is by overwatering. So your snake plant wont die of an undersized pot. At least mine doesnt. But yes it halts the growth of those towering spikes. So if you want a big plant, check if the roots are emerging out of the drain hole. If yes, the take the plant out, and pot in a pot of about twice the current pot's size. All the best