If you're under 5k chips, you're SOL. You'll have to aim for 200 reindeer later.
if you have 5,000 heavenly chips and a certain number of buildings (see here: http://cookieclicker.wikia.com/wiki/Thread:45712), you can then purchase the Season Switcher upgrade that allows you to switch between seasons, and change to Christmas to get the 200 reindeer.