I still think there should be a backup pitot that's deployable from behind a flap in the case of a disagree. Granted it wouldn't be failsafe, but it would be relatively immune from gaffer tape and ice accumulation up until the point of deployment (which might give you the survivability you need, especially if deployed automatically on a disagree - it'd also give the pilots an easily decipherable error message to base any troubleshooting on)