Luggage for kids

[mrsp1030]

Our two boys: 7/5 both have the smaller size pottery barn kids suitcases. They were great when they were small but now when we travel and need more than a few nights (especially) in winter, they are getting small. Trying to find a good choice. We are fans of LL bean adventure shuffles and have some large ones but curious of mediums would be good (wheels) or just do a carrying size bag. Thanks for any input.