good translating akrasia!
yes, going out to tea = heading out to his local for a pint.
as for informing him of your move, if it was me, i would wait until you have your flat lined up and the lease signed. why rock the boat? i do understand that you want the fairy tale that when you mention you're leaving, he will think "dear me, i can not loose this fine woman!" and then he will jog over to the local AA meeting.
however, alcoholic translator reports:
"i will quit drinking because i love you so much" = "i will drink anyway and hide it more"
enjoy your day at the cafe tomorrow!
naive