Have you heard of Zoom?
There's no magical dust that keep it from being ridiculously difficult. We have 3 kids within 17 month (twins boys and girl 17 months older) and we just didn't travel much for years. They are now 10,10 and 11 and are a joy to travel with but for a while it was just crazy. For a little reference I took them by myself from mainland to Hawaii (mom was already there) when they were 5/5/6 and that was rough enough. Of course, at those ages I had no diapers, they could feed themselves and carry their own luggage. I couldn't even imagine doing it at the ages you have.