Note that even if the base resource is infinite, food and booze would not be free: you still have to pay the workers, and I suspect that actually makes most of vodka's price.
So instead what you have is a highly competitive vodka and potatoes producer.
As pointed out by jamesqf's comment, that wouldn't change society much.
However it is also interesting to look at the geopolitics that could arise from this situation. Since selling those products is a live-or-die condition, we can assume that those products are heavily exported. And since they are extremely competitive, a huge part of the food consumed in other countries could come from your potatoes.
This has a major consequence:
In nearby countries, agriculture may be very under-developed:
because why would they bother with producing food that will eventually be more expensive than the one you are providing.
So you have a huge political leverage on these countries: If they do not obey you, you can threaten to increase the price of the potatoes, which would cause a famine since their agriculture is not equipped to deal with such a situation.
To see what that could do in real life, you can look at the relationship between Russia and many ex-USSR countries. There it's not potatoes but gas, but the consequences are the same.