For one, you misunderstood me. I suggested redeeming when the cash rate is higher than 1.2 x the replacement value of the points needed. If you can replace the points at 0.5 cpp, that would mean you'd go for an award if the cash / <points required for redemption> ratio is above 0.6 cpp.

For another, I do not think your maths checks out. If you do 70 nights total, surely there must be some without award inventory and many in which you cannot get more than 0.6 cpp. In my experience, award inventory is particularly limited at aspirational properties like the IC Le Grand. So I am somewhat questioning the total of 3-4 m points redeemed if you select between cash and award based on availability and my criterion.