I made a dish that used a small amount of wine and now I'm wondering how long I can keep the rest of it for next time.  I know you wouldn't want to keep good drinking wine around long after opening it, but does the wine get too bad to use in cooking quickly?  It's Chardonnay, if it matters.  Thanks! 
Opened wine spoils fast.  Red wine lasts about 1 day, white wine lasts about 3 days.  You can prolong this slightly by putting it in the refrigerator, but only by a few days at most, and it depends on the wine.  It may be "safe" to consume for much longer, but the taste will be way off, even for cooking purposes.  If you've opened it - finish it.  ASAP.  There are exceptions: "Cooking wines" such as cooking sherry and rice cooking wine have an array of preservatives added and will keep for much longer.  But don't leave perfectly good Chardonnay just sitting around to oxidize. 