I would think you could start playroom time now.
1. keep it dark, low light.
2. let them explore, you sit and watch, leave them be. having some toys in room would be good idea.
3. you can feed them treats.
4. bring SLEEPing pouch, at end of playroom time, turn up lights some and offer them sleeping pouch. they should go back in easy, but give them some time to decide they want in pouch. if not, then you will have to put them in pouch.