I am currently taking it online, and it is a lot of work. It's not necessarily super hard, a lot of it is just very tedious and mind numbingly boring. (in my opinion anyway!) The class itself is much easier than say a college algebra class is, as far as the actual math you're doing. I don't feel like the workload is any heavier just due to being online though, it's just the nature of statistics. A lot of the calculations are just plain time consuming, and some of the concepts can be difficult to grasp quickly. I cant speak for anyone else's class, but my instructor is always there should we get stuck on something. Even if you don't have the best online instructor, saying there's no one to ask for help in an online class is a copout. You might have to put forth more effort than in an in person class, but the help is available. Every school has a tutoring center, and khan academy, patrickjmt, and youtube are all great resources to help you should you really fail to grasp something.
As far as what you can expect, I know at my school, all the math classes utilize an online website to do all homework and quizzes, regardless if its on campus versus online. This software is immensely helpful, and has step by step examples and videos to help you if you get stuck on a particular homework problem. Since the in campus classes use the exact same thing, personally, the time I save commuting to campus makes up for the inconvenience of not having an in person teacher to help.
If you are not self motivated and dont use every resource available to you, I can see Stats online being a problem. It is very time consuming, so if you don't put in the time at home, or let yourself get behind, it may not end well. This fact is even worse in a summer term. If you're taking it in summer I would be prepared to be doing several hours of Stats a day. Additionally, learning all of the TI calculator shortcuts for stats will save your sanity, so I would try to learn all of the shortcuts as soon as you can. There is one for almost every complicated 10 step calculation.