They need nothing more, to sleep for two hundred years, than a comfortable bed, and a cool temperature in order to induce the hibernation state. Now that comfortable bed is one thing. The aliens have an arm running down the middle of the back, and therefore a slot in the bed to accommodate it, and therefore they don't toss and turn much. After two hundred years you would have one heck of a set of bed sores. Get a good supply of body fat, and you can actually go for a month without eating.
Bears only have to extend that a few times.
But even if you were able to drop your metabolism to one percent of normal, a two hundred year trip would mean that you would have to pack on a two year supply of nutrients. That'd be a fair sized pot. The aliens, though, haven't developed hibernation to get them through the winter. Or, rather, their periodic winters are four hundred thousand years long. Let's say that you can drop your metabolism to one percent of one percent.