Instead of locking everything into one deposit, split it into rungs that mature at different times. Each maturing rung rolls into the longest tenor, so within one cycle the whole ladder earns the top rate while cash still frees up every rung.
Interest is paid at maturity and computed as principal × rate × months ÷ 12. On maturity the whole amount (principal + interest) rolls into the longest rung at that rung's rate. Rates are assumed to stay where they are today.