In theory, it should be fairly simple to keep working while on vacation. I'm currently in Orlando for spring break and purposely stayed in a place that has high-speed internet just for that purpose. Unfortunately, when you aren't at home, there are far fewer factors that you can control. The main issues are:
Internet access has been intermittent, as the hotel is new and they still have some kinks to work out.
There is some kind of insane firewall here that is making it difficult to do much.
The schedule during vacation is not as easy as sitting around at home, and some days the time to complain about the internet access and to try to conquer the firewall is just not there.
My Spanish is not that great. Most of the people that are here to complain to can't speak fluent English, and some not at all. My Spanish is fair but not good enough to communicate seamlessly.
So, I am available, sort of, if a client has a problem and needs to get ahold of me. But, getting real work done is difficult enough to make it worthwhile to wait until I get home. That's the only lesson I have about freelance writing from a hotel- you can try, you can plan, but ultimately you are at the mercy of hotel employees and wiring.