Question about a Transfer Case seal leak. Hi Everyone,

I have an 02' Ranger with about 120K.  Recently I have noticed a small oil stain under the truck close to my drivers side door.  Smells and looks like gear oil.  I am thinking based on the location it is the rear outputshaft seal leaking fluid. 

I am probably getting what looks like a couple drops when leaving the truck alone after driving it.  Maybe the size of a quarter.  My question is could I leave this leak as is over the course of winter?  I ideally want to make it to spring when I can really crawl under and replace it.  How long would it take the front diff or transfer case to run low on fluid at that pace?  I drive the truck seldom, more in the winter, but usually about 3K miles a year.

Thanks for any help!  