There's not that much mystery to it really. Coffee doesn't have to be made from arabica, it can be made from all kinds of stuff, including chicory, which would in fact have been extremely common in Tolkien's day - its only lately with fancy city types wanting fresh-ground-hand-made £200 a cup coffee that us Brits have got all 'sophisticated' about the brown stuff. Maybe Tolkien would even have Camp Coffee (we all remember that stuff is we're over a certain age). If it wasn't made with chicory it could be brewed with acrons and other nuts.
Sugar? Sugar beet. Grows everywhere.
Tea? Dunno about that growing in different climes. But again tea does not have to be made from the usual leaf. However here, I think Tolkien as a Brit would have sniffed at the very thought of namby-pamby 'herbal teas'.
And the tobacco thing was cleared up because the plant even grows in the arctic and you can easily grow your own (and legally too) in an English garden.
