Cancelling AmEx Platinum

Without another AmEx:

--Up until 60 days one can get full refund of $450;

--After 60 days, one can 1) get an exception, 2) downgrade to a lower-fee card or 3) apply for another card and then cancel Platinum to get fee prorated,

With another AmEx:

--Up until 60 days one can get full refund of $450;

--After 60 days, you can 1) the above first two options, and 2) get the fee prorated.