Many people have received delivery estimates and are reporting their Retina iPad minis will be arriving as early as Nov. 15th in the UK and in the US as early as the 18th from UPS, according to 9to5Mac readers. Although Apple is stating Nov 21st for most of their Retina iPad minis. Shipping dates from Apple are 1-3 days or 5-10 business days in launch countries.
iPad mini availability might be tight during the holidays. The iPad air might be easier to get your hands on as opposed to the iPad mini with Retina which is at an estimated 2.2 million units.