I guess my previous message was not clear nor exact.
After having measured correctly my cabins, what i have in mind is to remove the mattresses and to replace that by a full size bed.
in that case, I can put a slatted floor and a mattress. It would fit.
The only thing a loose is a bit of bed width but it does not really impact as the current
bed size is in fact full at the head
and queen at the feet which makes that anyway is is somehow a full size bed in fact.
I will use the spared space to order some stuff in my cabin
Did anyone do that already?