We set up a mini kitchen in the dining room, with an electric camping ring on a worktop protector, a microwave, a kettle, a fridge/freezer and a toaster. So we had lots of pasta/risotto and stuff as well which wasn't too bad.
Washed up in the bath. Not fun!
Agree, dust gets everywhere.
If you have a door from the kitchen onto the garden, ask your builders to use that, rather than the front door, then tape a dust sheet around the hall side of your kitchen door. Dust will still mysteriously appear but you'll keep it to a minimum.
We stayed with my sister for three days as we had our heating done too so no heating or running water for a while. Sadly, we still didn't have either when we got back and we weren't prepared for that! Stock up on bottled water and ask them if they can turn the water on for you to refill bottles as and when. We didn't have drinking water for quite a while.
Mine were 2.6 and 11mo when we had it done and they got used to napping through a lot of noise. Didn't seem to disturb them as much as expected.
Above all, remember it's only a short-term thing and it'll be worth it! I still get a little excited feeling when I look around my gorgeous kitchen, eight months on.