Aimzee,
At least one of my credit card programs offers "temporary" numbers - a one-use only number that links, once the transaction gets back, to your original credit card. That way there is, at least as they describe it, no risk of a re-use of a stolen card number.
You might ask about that alternative.
MrGimpy,
I understand that they allow less than 90 days, but that is a courtesy. If a customs officer in any country is having a bad day, you have a bad day, and may get hit with violations of laws you've never even heard of. I've been down that road more than once, so avoid problems wherever possible. A good example is clothing - you may buy jeans at Sears in Chicago, but they were made in Lesotho. Unless you have a receipt from Sears with you when you reenter the US, or a declaration made at customs before you left, those are foreign jeans, and if the total of foreign stuff adds up to $400, you pay taxes or fines. Even my t-shirt is foreign-made.
It is all beyond absurd, but the law is the law.