Seriously, having hired and driven uber mondeo with heated screen, I wouldn't buy it or even consider it with a heated screen! The fine elements cause fine starring at night with oncoming headlights - far from increasing forward vision (which granted for 10 minutes on a frosty morning is excellent) it hinders for hours of night driving.
And as a bird watcher, it is noticible when you park up and just want to admire the view, or indeed look through binoculars (might be true for beach birds too - or is that sexist?)
I go with the luke warm water bit - it really does only take about a minute two slosh front back and side screens, and squeegy down - you also get a cleaner windscreen removing all that ****ty road salt...
Be greatful you don't have the promised heated screen.