Surprise boxes or how to survive travel with children

We’ve gone to Wyoming every summer since we’ve been married (and I’ve gone every summer but one since college).  When the girls were small,  Bill didn’t have much vacation time, so we flew but eventually the girls couldn’t travel for free in our laps and paying for four seats didn’t figure into our budget.  But no matter the mode of travel, there are two necessities for travel with children to go well–plenty food and drink (and not at airport prices unless in dire need) and something for them to do.