My experience with contracts was more as a business person than as a configurator.
What we did in our company was to start negotiations about a possible extension of the contract (if automatic renewal process was not already agreed upon certain conditions, of course) at least 1-2 months before the expiry date.
I understand that the time to finalize negotiations can vary per country, industry and company, but for sure your client can tell you how long it usually takes him to handle that.
Why can't they follow the same approach as us and start negotiations earlier?
You can configure follow-up actions for contracts close to expiration.
Why they cannot simplify the renewal procedures, so that they take less time?
We had no commercial ERP system, this is just a good business practice.