I'm still new at this, haven't hid my first cache yet. (Working on it ) However, the idea of placing a cache while on vacation, sounds like fun. I bet if you looked into it you could find a local geocaching club, through which you could maybe connect up with someone who would take responsibility for the cache.
This would allow you to meet new people, (the club members) and be able to seek and find a good hiding spot in an area you are visiting. The down side would be the cache would be in someone Else's name, but you would still have that warm feeling of knowing it really was yours.
Of course this doesn't change the rules, if you cannot find someone to cache it with you, and take responsibility for it, you would not be able to hide it.