It might be. I usually store whites in the fridge and reds at room temp. But really, when it takes a week to drink the bottle, you can't do too much about the last day or two.
Keep it sealed as tightly as possible, and recork it as soon as you pour a glass each night.
Ok! I'll give it a try next time...just recorking and putting it in the cupboard.
You can see how I could benefit from a smaller bottle, though...huh?