I read somewhere, maybe even on this board, to put a marble under the quilt. This will raise it enough that you won't pin the floor and it will roll to the next spot. Haven't tried it but it sounds logical.
Also, if you belong to a church, usually you can ask and they'll allow you to use their tables. Push several tables together, depending on the size of your quilt, tape and pin as usual. This would save your back too.
I'm sure you'll get some other good answers here too.