You don't have to transfer all your points to the rewards cards when you order them. I do mine in stages.
You only have to put $20 on one to order a new reward card & have it mailed to you. So that's what I do. Then the card usually comes in about a week or two.
Once I have my card and it's a month till we go, I go online and transfer all the remaining points EXCEPT $10 worth to the card. (the transfer has always been instant for me)
Then I let any last-minute points grow up till the day before I go. Once you already have a rewards card, the minimum dollars to add is only $10. So by leaving at least $10 in the account, you know you'll be able to cash out for the exact amount you have -- for example you leave $10 and have $6 more new points added that month, you can go online the day before you leave and transfer the remaining $16 to your card.
I like doing it in stages because once you put the money on there it HAS to be used by the expiration deadline. By only putting $20 on there to start with, IF your plans change or get cancelled, you haven't put your whole balance at risk. But you still have the peace of mind of knowing you've ordered your physical rewards card early enough to be sure you'll receive it.