WTD when no training races before the A race?

I have been wondering this for a couple of weeks now, but the Plan Builder has really accelerated this question. What do you do when you a training race (or races) is not an option before your A race?

Here is the situation: My A race got moved up to 16 May. I was going target a series and have that race be a B race. But do to major changes in event approval, that plan has been shelved.

I have looked and there are no races before my A race that I can reasonably get to. (up to a 5 hour drive, nothing). just finding a mtb race to train with is going to be nearly impossible to find.

Do you just go with experience? How do you handle the Plan Builder requirements for B races?

Thanks TR family!