Is it safe to let a dish defrost during travel for several hours?

I'm going to be traveling to a relatives house for 3-4 hours and I have some dietary restrictions that I don't want them to have to worry about. I was planning on cooking a stew, freezing it, then traveling with it in a container. I won't have a cooler or any cooler packs with me. Will letting it defrost that long on the journey be safe to eat? It won't have any dairy or meat in it