Hi Jeremy, the official stance is no exceptions. However, if you take the time write a letter to them, explain that the trip was delayed and you had intended to take it in your current membership year and would they consider extending your membership year by X amount of days to allow you to acquire enough tier points for a Silver/Gold renewal, they will consider making an exception (they did with me).
Exceptions are done on a case by case basis, and there is no guarantee. Consideration for exceptions is ONLY possible if you put the request in writing, and exceptions to the rules will only be considered for Silver/Gold memberships. Note also how I recommend that you phrase your request, as outlined above.
In addition, I recommend you write to them right at the end of your membership year, otherwise they will merely respond saying you need to fly with them some more before the end of your membership year etc. I hope that helps 🙂