My cat, Snowball, has dry food available 24/7, but I also give him two or three teaspoons of wet food every morning. After I take it out of the refrigator, I warm it in the microwave for 20 seconds and check to make sure it isn't too hot for him to eat.
I feed my cats dry too and they are allowed to eat at will, except for Amber. She seems to like her food cold! I have warmed it in the microwave, just till it is warm and she walks aways from it. If I let it sit out a little so it warms on its own, she will eat then. Talk about finicky