Since the car only hold 4 quarts ( unlike the many gallons my DP uses) synthetic costs really isn't a a problem on a 25 grand car I would think. But then again I tend to look at things differently I guess.
The explanation given to me........... The reason Honda uses 0 w oil besides temp rating is the engine is designed around it and has been for many years!! . My 06 uses 5/20. Honda does this not primarily for cold temperatures but for mileage ratings on the engine. The oil is designed to lube properly and provide low friction in the engine designed to close tolerances.
The good news is since you own it you can do whatever you feel is right. My feeling is 5 bucks more a year on my car isn't even a measurable % on my overall operating costs. The lower mileage a higher weight oil will.get you will let you pay that 5 bucks a little at a time LOL