Thank you
@sudoer,
@wsthong,
@N0mad,
@_TheTraveller_, and
@0x012fd0aa for your informative and quick responses: much appreciated.
My progress so far: I rang the Amex Concierge Team (I forget their actual name but it was something like that) and spoke to a very helpful lady. After explaining the benefits of my new card to me, she forwarded me on to another team who dealt with setting up a Priority Pass account. This lady (the PP one), told me that the physical card takes 4-6 weeks to be posted out (a very long time), however a ditigal copy will be available for me to use in a fortnight (which is just before I go oversesas). She did say that I'll need to call back in a fortnight to get my PP number.
If my PP number arrives in time and if I have any trouble using it digitally, I'll let you know.