[nullwasamistake]

I may be wrong, but I think you can tell IPVS to schedule using tuple hash only using Direct Return mode, which means no stored state for connection tracking.

Edit: doesn't appear to be true, but it uses it's own "lightweight" connection tracking table so you can unload conntrack modules from kernel.

Realistically IPVS can probably route 40 gigabit of traffic per instance. Combine that with DNS round robin and maybe even multi-homing at the front and you could handle basically anything