My uncle drove from Illinois to Arizona in his '08 T&C van equipped with AWD. The tires on it will definitely not last another road trip, they are right down to the wear bars. He does a lot of highway driving and commutes in snow about 4 months out of the year. Traction in ice and light snow is his number one concern but a new set of tires will also need to perform well on his return trip back, at least 1,550 miles.
OE size is 225/65R16 with 100S load rating. I'm definitely not sure if I would recommend an all season set or winter-specific set. Not to mention the availability of dedicated winter tires in downtown Phoenix is very slim.