Advice needed!

LO is now 14.5 months. We have confirmed and bought the tickets to iceland and this will be our big trip for the year. LO will be almost 18 months then. We picked Iceland because according to DH, it is quiet enough so we don't need to worry about going everywhere in a tight schedule. It also stays bright for long hours so we may not even need to adjust our clocks and go through the jet lag trauma for LO!

Since the tickets got quite expensive (3k for 3 seats), we haven't even booked hotel or car yet, and DH has a big plan of NOT adjusting the clock (which means we'll be eating dinner at 11pm local time, but 6pm our time..etc), he has the big brilliant idea of doing groceries and making our own meals most of the days. This actually makes sense as it would be nice to drive to a location and have a leisurely picnic within the beautiful scenics of Iceland. IF our son is not just 18 months old.

At 14.5 months, he eats pretty well on his own, but he still creates a mess, and only when he's eating on a high chair / at a table. I haven't really tried having him eating while seated on the floor, or unconfined. I usually allow at least 30-45 minutes for him to eat his main meals... but if we were to do a picnic, or preparing food while eating at a non-planned location, I am not sure if he can feed himself efficiently, unconfined, in a shorter period of time.

I also wanted to pack in the 5 food groups as much as possible in the week we'll be on this trip. While I could give him squeezies for veggies, and make grill cheese and cook simple pasta (for grains), and cut up some fruits is easy, what am I going to do with meat? I kinda not want to deal with cooking meat while I am on vacation. Should I feed him beans for 7 days straight?

For us we can do cold cuts, bread and cheese, sandwich and what not, but LO doesn't eat sandwiches efficiently without decomposing the sandwich and smearing it allover himself. I also don't want to give him deli meat / cold cuts yet.

I guess I could go back to the spoon feeding route and bring along baby food jars (which I will have to just in case), but now that we are passed 1 year I am actually not sure if those will be nutritious enough for toddlers older than a year.

Not to mention I am not sure if it would completely ruin my experience if I have to come home and prepare the meals for the next day for the entire vacation. So I am looking for the quickest / easiest way possible without compromising too much on nutrition values.

Do you have any experience and any advice on this? Or have you done a picnic with a very young toddler before and was it successful?