Have you need the really nice food flasks, for the first day you could always make a nice homemade soup and take in the flask to sip as and when you wanted with some wholemeal bread to dunk as your B if you wanted.
The cheats tomato soup can be made in 5 mins in a food blender if you are stuck for time and then yo just heat the amount you need and flask it - i think the recipe is in the forum but i can post if you need.
I was travelling a lot last yeah and i used to pop to a Tesco express for food. Their spicy chicken pasta pot was low on syns (I cant remember the exact syn value) as well as buying salads and packs of cold meat. To keep thing cold i used to have a little plastic tub and then used the ice machines or ask for a jug of ice from the bar and kept my food on ice.
If you have Breakfast in hotels, i fill up on mushrooms and tomatoes, beans and bacon with fat cut off (allowing syns for fat used in cooking), then grap a bowl of fruit and also take fruit back to my room with me to eat later. I use to find that if i could maximize breakfast it could keep me going for the most of the day.