The only problem with that solution is that it may cut the difficulty in half. Decreasing block rewards generally have a direct correlation with decreasing hashrates. Hopefully an increase in price will offset this.
That is normally true when there is no activity against inflation, but as you said, an increase in price would offset the reduced hashrates.
We've also noticed that despite the falling price, mining hashrates are still within 20% of their peaks on a regular basis, so demand to mine the coin is still strong. We may see a temporary drop in mining power, but it should re-correct itself at the new equilibirum.