I wouldn't think that 0.4" of additional ground clearance would help you significantly, but if that's what you want then go for it. You may want to check with local regulations about having proper odometer readings though. If you drove 10000 miles this winter on those tires, your odometer would only read 9660.
And if you are worried about the rough roads, remember that deticated snows are much softer than A/S or Summer tires, so the ride will be smoother no matter what.
Either way, don't let these minor issues stop you from doing what you want. Best of luck!