Been there done that. I'm much better. At the suggestion of my sister, Thursday is BOM day. Every Thursday, I put EVERYTHING else aside and work on my BOMs. If I have completed all the BOMs I have for that month, I work on an old BOM that required a lot of embellishing (no different from your 81 pieces).
Starting an online BOM late? If not required to be in order, I start with THIS month's BOM. For instance, I have one from fat cat patterns that I will be starting in April.
However, given that you are unable to put aside a current project just to work on the block, I don't think clubs are for your future. Wait a few years and you can buy the pattern all at once. Then pick your own fabrics.
I'm doing a BOM from my LQS that started last Nov. and am way behind on that because of various things going on with remodeling, illness and mom's surgery. The Thursday requirement is really helping me to get caught up. Part of my lack of motivation is that I'm not big on the color choice, but it's for my Mom and she loves it. I prefer buying the pattern, buying my own fabric and then following steps month by month.