Heck I live in Charlotte NC and I haven't been able to get out with the top down much and all I want is 44 degrees! Snowed again here today
So over the weekend I changed my plugs, cleaned up the engine under them so if they leak I'll know in the future. Have 54K miles and only one tube had a speck of oil in it. Only thing I might do is replace the rings on it, but in no hurry, everything looked real good!
As for changing the tubes and o-rings, I do a lot of things on my boxster that might not be needed, figure if you do it now, probably won't ever have to later. Often I do things just for the learning experience