I know you're making your own purees and freezing them at home, but if you're not opposed to purchasing a couple of jars of the same foods your lo is already eating at home to have for these outing type situations, they would be quite convenient. I know they make more organic options now than ever which I believe have less preservatives and added sugars etc. This way they can be served right out of the container at room temp. I work full time and would like to puree food, but find it hard to fit it into my schedule. I have been using the store bought stage 1 baby foods by Gerber, Beech Nut, and Earth's Best and my DD eats them with no problems.
Best of luck. I know getting out of the house is both necessary and enjoyable. I hope you find something that works!