Everything else about a medal order can be fixed later. The date of the race cannot, which changes how the order should be planned.
Work backwards from the event, not forwards from today
Set the delivery date a clear fortnight before the race, then the ship date, then the artwork cut-off. Those three dates are the order.
A quote with a lead-time range rather than a date has moved the risk onto you.
Know when sea freight stops being possible
There is a specific date after which the only way to hit the event is air freight, at a different cost.
Ask for that date before committing, so the decision is yours and not a surprise.
Order a buffer
Entries creep up in the final fortnight, medals get damaged, and some go to sponsors and volunteers.
A sold-out race cannot re-order into a fixed date, and a small buffer costs far less than a hundred finishers without a medal.
Keep the die
If the event repeats, the same tooling can be run again the following year with only the ribbon changed.
That is the cheapest year-on-year identity there is, and it needs planning in year one rather than year two.