I don't see how "I would have to accrue unexpected and emergency debt to manage this expense" is any different from "I can't afford this expense"
1) I have the cash ready to spend right now or in liquid assets.
2) I can get the cash, but from an account/asset I'd rather not withdraw from (IRA, jewelry).
3) I can go into debt to pay it, and it wouldn't make a big difference over the next year.
4) I can go into debt to pay it, but my financial situation would be close to bankruptcy over the next year.
5) I can't access that kind of money by any means.
A good survey should iron out this spectrum of "affording" the expense to make the result robust and easy to interpret.
I'd say that both count as "struggle", though