I'm not really a fan of using citrus fruit in non-sour beers, as by the time you ferment the sugars out of the citrus you're just left with a sour flavor that isn't really that pleasant in a clean beer. The zest, though, is where all the citrus oils are contained, and is the best way to get citrus flavor and aroma into your beer without the unpleasant sour/bitter flavors associated with the fruit itself. It's fine in a Berliner weisse, but not ideal in a hefe.
If you can get blood oranges right now, you might have some success with zesting them and making your own extract that you can keep until the warmer months. Try to just use the outer layer, not the bitter white pith. Not sure how it will hold up, but it may be worth a shot. I like to use 3 or 4 medium-size oranges in a 5-gallon batch. Normally it goes in right at flameout, or once the wort cools to 180F or so. However, you could try making a tincture with it by covering it with 8oz or so of vodka, and storing that until you're ready to brew. The flavors should be extracted into the vodka, which you can add to your beer when you brew it. You can even add it at bottling/kegging to taste.
As for how long it will last? Not sure... you could always try throwing it in your freezer to keep it fresh longer.