Artist's description from DA:A year after the war began, Matilda dies from a brain tumor. Now without Pinkie around, Cranky has no one. He instantly grows salty and sour again, immovably dreary and pissed at everyone. He begins smoking again (he quit when he moved in with Matilda) and never ever goes any further than his front porch.
Granny Smith makes sure Sweetie or Twist brings him something to eat every now and again. But he was not well. He lost weight and was sick all the time. He was a lonely widower with nothing to stick around for.
Then Pinkie came home. Granted she was only in Ponyville for a few days but just long enough for her to see Cranky and for Cranky to see her. She dragged his sorry ass along with her when she moved and hovered over him while she stareted up her own bakery. It was like living with a tyrant, he'd complain, she forced him to eat and see a doctor and splashed him with water if he tried to light a cigarette. She put him in charge of watching Harrison when she was with customers or out running errands.
For ten months d he lived with her and her son. He died in his sleep one summer night and Pinkie had him buried next to Matilda back in Ponyville.