I'd go high - better radio coms, if you have a tailwind your time will be shorter, and your fuel consumption will be much less.
Watch the Vne as it decreases with altitude (but as a FW driver you know about TAS being higher for the same IAS).
You'll also be able to watch the weather, and God forbid if the engine fails, you'll have more choice of landing places.
Enjoy the flight and take a large storage card in your camera.
Happy new Year!