Another idea if you do not want the extra hardware and will give up a little bit of resolution.

I had the same problem in the past, using a LM34 and a pressure sensor with an output of 1 to 5 volt = 0 psi to MAX. Left the VREF at VDD. OK for the pressure sensor, took the ADC value from the LM34 *2. This gave a 2 degree resolution for the temperature though, and I can not remember but I think the ice water test was off a degree or two also.

Not perfect but the pressure was the critical thing on that application.