You can certainly rack into multiple smaller containers. What is nice about that is you can mess around with them individually if you want, such as adding spices or other flavorings. When I make wine or mead, I typically make a little bit more than I need and keep the extra in beer bottles under airlock (#2, I think). When I rack, I use the beer bottles to top up. I don't rack very often, so I don't need that much on hand. I've also topped up with boiled water. If you're topping up a 5-gallon batch, the amount you're adding doesn't make much difference in your gravity. Some people don't want to dilute, so that is why they use marbles or top up with a similar wine or mead.