I have a situation where my Green card I-485 approval has been done ( according to USCIS site) - and since this is approved, the Advance Parole has been denied

I am scheduled to travel to India on 28th May for some important personal reasons.

Can you help me figure out if
1. I can travel abroad and come back on my L1 without any issues

2. I believe if i get my approval letter, i can go to the USCIS office and get a temporary stamping done. But if i dont get any documents from USCIS before i travel, what are the options that i can use.

3. My wife and son are currently in India.. the idea was for them to travel back on their valid L2 - if we dont get the Green cards well in time, how can they travel back?