Frozen Nest

I've just had a reasonably bad experience with my nest.  I guess I had recently agreed for the nest to manage our heat based on the auto-away setting.  When I got home last night from work, the house was crazy cold (60º upstairs), despite the fact that the boys were home all day.  They were home, but by and large just sitting in front of their computers, not doing much of anything involving motion, which the nest would have picked up on indicating that they were home.

The reason that I'm unhappy with this nest experience is two-fold:

• The low temperature tonight is forecasted to be in the single digits and I'm concerned about pipes freezing.  I wanted to keep my house reasonably toasty to minimize the potential for burst pipes and expensive clean-up.
• The nest was never able to bring the house up to temperature.  When I went to bed, the nest was up to 65º - not comfortable - and the furnace has been running non-stop.

What this points to is the following:

• The auto-away feature should have an additional limit: this should be the amount of time that you are willing to wait for the house to get back up to the target temperature.  This should take into account your house's modeled behavior and the current and forecasted temperatures.  I should be able to say that I never want it to take more than 1 hour to get to temperature.  The nest would then ensure that it could get the house up to that temperature (and if somewhat extreme temperatures were forecasted, it would take that into account, dynamically setting the low temperature mark).

Let's get on it nest!  Or other software providers, now that the API is supposedly available.