I have one of these andlike it pretty well.It expands and can fit a large amount of luggage. I also has wheels and a telescoping handle to cart it into your room or where ever.
https://www.amazon.com/KURYAKYN-HARL.../dp/B001K2INQK
The down side is it doesn't sit well on the stock luggage rack. I made a platform out of 3/8" black ABS to enlarge the surface area of my OEM luggage rack. This allowed the luggage to sit flat as intended and be supported. The platform I made installs and removes easily from the OEM luggage rack. If you have an aftermarket , larger luggage rack this wouldn't be an issue.