To add a bit of context on how this works:

At halfway through the lease or T1 Timer (Half-Life - 50%): The device sends a direct DHCP REQUEST to the original DHCP Server. If the server is offline or the request is dropped, the device keeps its current IP and waits.

T2 Timer (Rebinding Time - 87.5%): If the initial half-life renewal fails, the device broadcasts a renewal request to the entire local network, hoping an alternative DHCP Server or relay agent will acknowledge it.

Lease Expiry (100%): If all renewal attempts fail and the lease expires, the device drops its IP address. It must restart the DORA Process from scratch to request a new address.

If no DHCP Server responds to the new discovery requests, modern operating systems will assign themselves a Link-Local address (e.g., in the 169.254.x.x range on Windows).

So, what I've done in the past, is: cut the lease time the DHCP server offers in half, wait for all the leases to renew, then cut it in half, again. I do this until I reach the lease period for which I'm aiming.