I'm a risk taker when it comes to combining tickets.

I've been accommodated (very well!) by delta when a two-ticket itinerary created a problem.

I would absolutely position the night before in this case, if it was me. I do not like to cut things close on the outbound. In addition to the potential costs (which could be zero), also consider the disruption to your enjoyment of the trip if you get a misconnect on the outbound.