since you are traveling over seas... from my experience flying you could check separate bag as medical supplies and that should be a free luggage check items or could take enough diapers for a few days and source local diapers but that could be a interesting journey. pretty sure any pharmacy or supermarket has diapers just not sure of the quality might so some research.
As far as the Hotel... depending on the quality of the hotel they might be able to have a mattress protector available to use or underpads i typically take 2 underpads with me when we travel plus one more for the van seat
Just my 2 cents

_________________
Skype Me..
specialchildfs@outlook.com Saving the world one family at a time, restoring hope though compassion.