How long will you be travelling oversea? 1 year? 5 years? 10 years? or simply 1-2 weeks? Overkill for you to even consider or entertain that kind of question if it is just a short trip...unless you are going to some of the most inhospitable environment in the modern world. Your proper camera bag would more then enough even if you are away for more then a month!. Let's not be too overly panicky.
I don't even use a dry box for my DSLR/lens since the day I bought them and it has been 2 years plus and they are still in fine condition. I use my gear 2-3 days every week.
i also think that dry cabinets are for more humid countries. when u travel u also use ur camera every day (well, i did anyway) and i doubt that fungus will have a chance to grow as the air is constantly moved around.
Where will you be going? If you are going to any of the temperate country, then a dry cabinet will be useless. The weather there are usually quite dry. The use of dry cabinet is mainly for those places with a tropical rainforest kind of weather, like Singapore where the average humidity is more than 90%.
In fact if you go to Europe or USA, the photographers there may not even know what is a dry cabinet.