I have this problem all the time but for me it also depends on what time of year. If it is the summer I will water everything and get it out of the high light area for even just 7-10 days.
But now that it is September I don't have to worry about that. In fact, I was just away for two consecutive 10-day periods (could water once in the middle) and things weren't really all that dry when I came back. Anything that is recovering that needs special attention for root growth pose difficulties though. Certainly use sphag on some of those, but be sure to let things air out once you are back.
I guess I assume one 10-day trip won't kill anything, it might just be a little unhappy when I come back, so I then need to be sure everything gets what it needs. Haven't got much experience with the longer times though. For over two weeks I think you would need someone.