It's a good idea. You can use one of those rigid plastic barrel liners (~$20, likely to last a long time) or a similar-sized cheap tub (~$5, unknown lifespan but mine have lasted three years above ground). My lotus are on the patio and aboveground, but I would bury the tub if there was a convenient place to do it.
Bob

I'm thinking 18 inches down, in some kind of bucket, or maybe plant liner, and it should come back the next year.

you should start your plant as soon as you can get it this year. It's probably not going to bloom the first year. you don't need to plant the tuber to deep as it will send runners as deep as they can go as cold weather comes on in the fall. These runners will make tubers at the bottom of the container and come up next season Sometimes you can ask your dealer if yhey would send you a runner if it is to late to get a tuber. They grow well and will make a two or three tubers that will come up next year