Players are free to leave the ladder and re-join it at any time with no penalty. Leaving the ladder does not delete any on-going games, it just stops new games from being created for you. Your rating continues to be updated even when you’re not participating in the ladder...your existing rating will be used to rank you just as it was before you left.
Cool. It doesn't confirm you can go on a vacation with pending games but I presume you can.