I would use the Grand Hyatt in Terminal D. The lobby has some comfortable seating and should be pretty deserted; the Moka bar or the Grand Met lounge would be other nice and easily accessible areas for a meet-and-greet that have the added advantage of providing an opportunity to temporarily remove the otherwise mandatory face masks if everyone feels comfortable doing so.
https://www.hyatt.com/en-US/hotel/te...w/dfwgh/dining