Please talk to your non-profit's board and lawyer before acting on any of the following to get the most appropriate advice.
You contact the estate of deceased and ask them to divest the individual from the corporation.
After that, although the article is still valid, the board may need to introduce new individuals to ensure the original corporation is held to be valid.
After this, an account might be feasible, but that would depend on where the non-profit is encorporated. Some jurisdictions do not allow a non-profit that is inactive to remain in existence or to operate after a period of time.