After reading his glass options, I'm thinking a single IV and a round of upgrades to his 24-70 and 70-200 IS, plus a 6D? Having 2 identical bodies makes moving between them much easier, but it seems that you're all over the board, and sinking your entire budget into a single X isn't going to solve all your issues at once.
Not that spending money isn't fun, but hitting these upgrades now would make adding a 1Dx in a year just that much stronger overall.
I thought I was clear that I need to shoot both indoor and outdoor action so upgrading lenses I already have and getting a 6D will not provide a solution. Thanks for your input and for everyone who stayed on topic, you gave me tremendous insight. Since I have a respite between fall sports and late fall dance performances, I can wait a bit for the purchase. I have 2 more CPS 1Dx loaners to cover anything that may come up that I can't cover with my 5D2 and 70D. I know I can't cover volleyball in the venues I shoot so I think I will opt for a 1Dx just before volleyball season starts. Hopefully, Canon will have made announcements before my next purchase and drive the price down. If the announcement means I wait for the new camera rather than the 1Dx, then I can rent as needed.