Kenny mate, I just got back from the pub, I is tiddled, but I'm quite sure Ohm's law is relevant here. All the other features of the memory are constant, therefore, if you increase the voltage, current will increase and more (mili) watts will be created.
And that means more heat.
flops = City & Guilds part III Electronic servicing, Colour TV reception and Digital techniques, 1984.
But I've forgotten the lot now, there's more money to be made in other fields, unless you're really clever and get into research.