Help Needed: Stock Bridgestones safe in 20-30 deg F?

SeattleLion

First of all, thanks for the good advice about snows for the Z. Based on the advice of members, I won't be bothering. However, this still leaves open one question that has been bothering me a bit. Are the OE Bridgestone Potenzas manageable in colder weather? Most of our winter here is in the 20-40 deg range. Mostly in the 30's. According to the manufacturer, the Potenza loses flexibility in temperatures near freezing.

Another tire I found on tirerack.com is the Michelin Pilot Sport AS plus. This is an all weather tire with what appear to be better performance numbers than the Potenzas. I only have 1400 miles on the car, so the tires are not worn. I am just concerned about how the car will handle in the 30-40 deg F range.

Remember, this is my DD, so I am not looking for optimum ultra high speed performance. 4 of the Michelin's cost about $1,200 plus mounting. I would love to not spend that money.

Does anyone have winter experience with the stock Portenzas? What's your advice?

Thanks,
Bob