We did this last year during our renewal, with both kids, so I remember the details well.
The temporary certificate worked fine at the border for us. The problem was the airline check-in desk on the way back, which was much more nervous than the border police. The agent had clearly never seen the document before, called a supervisor, and it took about ten minutes and a phone call before they printed our boarding passes. Not a disaster, but not what you want with two tired children and a queue behind you.
What we carried, and what I'd carry again:
- the old card, even though it had technically expired
- the temporary certificate, original, not a copy
- a printout of the appointment confirmation and the renewal receipt
- for the kids, the same set for each of them
And get to the airport early on the return leg. The outbound was easy. Coming back is where they check whether you're allowed to live here.