You'd simply side step FaceID, let it do a passcode only "reactivation" after 48 hours, sleep it, try Face ID
Anyway, FaceID has been outstanding for me. It worked outside this weekend in intense [Orlando, FL] sunlight, inside line queues, in a couple of attractions (one with funky blue light and I was wearing 3D glasses), and when I swam up, under water, to the edge of the pool, checked my phone (pounded the last of my beverage

) I was especially stoked about the water resistance these past few days (even though I realize that's not exclusive to the X).