Wikipedia says 140k to LEO, 37k to Mars and 7k to Pluto. Still, there's excess capacity there if a roadster is about 3k. Does seem like they sent it as far out as they could with that payload.
the other thing is you're looking at max distance with full recovery of all cores (despite the failure to recover the middle core). If you went fully expendable on all cores you'd get a LOT more payload a LOT further.