switch between price plans during a poll run

Is it possible to upgrade to an upper price plan if the no. of participants has been almost reached on the actual plan limit?
E.g. I run a poll on a premium account and as the participants (voters) tend to reach 200 limit, can I upgrade to the business price plan and the poll continue for the next 1800 voters with no pause?

Yes, as soon as you up or downgrade a account the new limits take affect.
Please also see this: https://pollunit.com/en/questions/24/how-can-i-upgrade-my-plan