E.P.
I end up feeding my son out of the house a lot of the time, too (he's almost 1). It was definitely a learning experience (and still is) to make it as easy as possible for me while still allowing him to have the food he needs. I found some things that help. Get foods that you can quickly throw together to take out: dry stuff like crackers, cheerios, and I do cheat and buy ready made snacks to take, too. I keep them in a container that I always take out with me, so he can have a snack whenever he needs.
I add fruit and cheese and stuff in a separate container - just cut it into little lumps ready to pass to him. If I have time I cook vegetables and add them, too, although he doesn't really like eating veges on their own. He gets one 'meal' a day - something I cook and freeze, like vegetables and pasta, risotto etc. I bought a little thermos container so I can heat the food and keep it warm when we go out. That was a really good buy, I wish I'd got it ages ago but I thought it was too expensive.
I got a free sample of the toddler formula and he didn't like it. So even if I didn't think it was a waste of money, I wouldn't be switching. I hope some of the ideas above help
E.