The timing of the redundancy is somewhat irrelevant, that would only really come into effect if you decided NOT to return to work after the redundancy
The way it works with your 20% tax band is that it is pro-rated over the year so by 31-Oct you will have only used up 10/12ths of your 20% band and also you will have only used up 10/12ths of your tax credits as well so you will still have 2/12ths available to use against the redundancy.
This assumes that you won't have any other income over the remaining 2 months of the year to use up those bands/credits
There is no €200K tax free limit or threshold when it comes to redundancy so I think you are misinterpreting something from the Revenue leaflet
I would still question the current value of the tax-free element of future pension lump-sum
If you are scheduled to receive a tax-free lump sum of €79,815 in say 2022 then that is not worth €79,815 in current value, it may only be worth €70,000 due to the time-value of money. You should be able to confirm this with the HR or Finance dept of wherever you work