The most convenient way of importing a currency is a plastic card.
So, you do not have to puzzle how much money to change. Plastic cards are accepted everywhere.
We had one case when one plastic card did not pass (Visa Sberbank), we tried another (Mastercard Yandex). In addition, suddenly you want to go to Norway or Sweden. We were somehow near the Swedish border and all went to Sweden to refuel. In this case, you would need more and Swedish Kroons. The plastic card solves all these problems at a very favorable rate for you.