Rohebuks

I have a 5 year old and 7 month old. Any recommendations for car seat situation for transportation from airport to hotel and hotel to dock? I don’t really want to lug their car seats and have to shove them somewhere in the room but I’m also not willing to have them unrestrained (my 5 year old is small 36 lbs). I don’t have transport set up yet so looking for any and all advice. Staying at Grand Hyatt. Thanks! — looking for recommendations.