Now that we are in the 21st century there have been some inventions you may have missed - silicone chip gyros & accelerometers ? The best part is the Dynon & Trio ( maybe others) can default to a minimum or maximum airspeed ie , when autopilot engaged, if you're climbing it will default to minimum airspeed set if the rate is et too high & aircraft is not capable of the sustained climb rate OR if you command a descent rate that could result in a very high airspeed, it will establish & maintain the max speed set in setup menu.
You ask about ICE - don't go there !! These autopilots will still hold wings level .