Three rules:
Max safe silicon volts is always lower the lower process node you go.
Max safe silicon temperature is always lower the lower process node you go.
Silicon degradation incl. electronmigration is much higher the thinner the metal gate and the lower the process node you go (with higher current/volts).

So, at 45nm, you are going to have to stay lower especially with regards to voltage. That's why max Intel specified is 1.45V for 45nm and there have been many dead CPUs even under cold with volts just above this.

Staying 10C below 70C fully loaded in winter/summer is fine, but that's if you really are below it and depends on if you're one of the lucky ones with a working set of core probes. Most aren't and read unrealistically low values, unfortunately.