Tam, I am glad the pics are helpful! I think it would work really well for that type of traveling. I could completely see myself using it. :-) I don't think it would be really hot since you aren't cinching it tight against your body, there is still some air flow, iykwim. It is not microfiber, so I think there is some breathability to it. I think it would work well to keep your valuables close at hand, even if you had a second bag or stuff in a stroller basket. I am not a fanny bag person so this would work better for me.
My biggest problem so far with it... DS still rides in his sling once in awhile. He sees me in with this bag and keeps saying "Nice bag, Mama!!! Can I ride in it?" because he thinks it is a sling, lol! Try explaining that one to an insistant 3 year old. ;-)