My DS is in kindergarten this year, and our trip is scheduled for May 25-June 2, which puts us leaving immediately after K graduation. We've talked to the principal/administrator because of the weather issues we've had and the possibility of make up days added to the end of the year. The principal said his attendance had been good and it wouldn't be a problem, if he does end up missing a couple days. However, that is the end of the school year.
My DS was sick on Monday this week, and he missed school. He had enough make up work that he missed, it took almost 2 hours to get it done. Make sure you allow time to get the work made up, even in kindergarten.
I would talk to the school as soon as it starts, explain the trip and that it's paid for. It shouldn't be a problem.