They *might* be OK, but they'll be pretty carby, so I would personally advise against. When I first got diagnosed, I started having a couple of spoons of quaker instant for breakfast, and they didn't exactly do any damage to my long term results, however, they were definitely spiking my blood glucose quite a lot- because I tended to keep it in the low 4 range, I would have the instant oats and it would put me up to 6 or 7, so I was sort of within acceptable levels. Still, once I saw what it was doing, I stopped eating oatmeal altogether.
When I'm stuck at work, I eat things like boiled eggs, tinned meat, tinned fish, ham- stuff like that: it's very portable and easy to eat- I keep tins in my drawer for when I need them.