Hi traveling parents! Looking for flying/car rental/hotel tips with an 18 month old & 3 yr old, PHL to ATL. Do I HAVE to take my own car seats, bc that seems like a pain. Recommend "lap flying"? Recommend bed sleeping in hotel, or pack n play (yet another thing I'd have to baggage check, ugh)? Any advice on "dos" and "don'ts" help.. thank you!