portable car seat?

[mumbleboo]

DS is 15months so has a pretty hefty car seat. We're flying to hungary and will be going on 2 privately booked coaches whilst there, for 2 hours each way. I am worried both from the safety point of view and also because DS can't manage 2 minutes never mind 2hours on my lap! Is there any type of inflatable car seat/ foldable one/ seatbelt adjuster for his age range easily available or should i buy a smaller booster as something is better than nothing?

persoanlly i would just take his car seat.

dont think there are any small / light ones and defintiley no inflatable car seats.

Does he still fit in his group 0 car seat... which go up to 15 months / 13 kg?...

though if the coaches dont have proper seat belts you wont be able to use it anyway

are you sure Hungarian coaches even have lap belts and that he will be allocated a seat of his own ?

I have no idea about anything hungarian! I am reluctant to go myself tbh but there would be consequences if i didn't! I think his group 0 car seat is probably the best option isn't it. I am hoping for coach seatbelts, but he will definitely have a seat as it's privately booked for all the wedding guests. Thanks for your advice