Flying via Warsaw

I'm visiting Kraków but will need to fly into Warsaw/WAW. The flight lands at 5:25 PM on a Monday. Would you recommend taking the train to Kraków that night or spending the night in Warsaw and taking the train to Kraków the next morning?

How are the train schedules later in the evening? I know it won't be much time but is it worth staying in Warsaw for dinner, a few drinks, and saving a few hours in the morning to wander the city? Or is Kraków better for dinner/drinks on a Monday. I've never been to either city and, unfortunately, won't have time to otherwise visit Warsaw. I'll still have time to do everything I want in Kraków with either plan. Thanks for the advice!