Is it possible to transfer one-time credit card info to a physical mag stripe card?

No, this is not possible. Among other things, the value provided for CVV online (such as a one-time use credit card number) is a CVV2 value, similar to what's printed on the back of a Visa/Mastercard. (And is generally used for any "Card not present" transactions.)

On the other hand "card present" transactions require the CVV1 value, which is encoded on magnetic track. A one-time-use card on the site wouldn't provide that value, so it wouldn't be possible to build the whole magnetic stripe.