We'll have to deal with fiat or even gold as an intermediary for a while, at least in the areas that will have the most freedom from a practical standpoint!
There will always be a way, in most cases simply walking around asking at all the cash exchanges, gold and pawn shops, and wherever you find experienced people should work out ;-)
A few years from now? Who knows, I think we'll be able to spend and transact for most things simply since Lightning adoption will grow, but I'll also handle it it that doesn't happen...