I actually had a 12 year old cat who disappeared for about the same amount of time when we moved to a new house. It turns out she was hiding in the neighbor’s garage, but I don’t think they were feeding her. She came back and had lost a lot of weight, but she didn’t die. I’d put out some food, just in case she’s still around.
Maybe you can try to shake a cup of foot to entice kitty. That has worked for us in the past.
When you call for your cat, use a calm voice. They will respond better than if you use a loud shout. This is from our own experience locating an inside cat that went outside.
Had an old cat disappear for 3 months and then show back up on Christmas Eve like nothing was wrong. She lived another 9 months and died at home.