There won't be one. There is enough v6 expertise around that the v4 crunch will (eventually) be solved by moving to v6, despite the grumblings, and probably with some extreme tantrums along the way, judging by the comments on here.
I've had v6 for years courtesy of Entanet, though I had to build my own firewall/gateway router.
Sadly many manufacturers are still in ostrich mode though. I recently bought a TP-Link TL-WA901ND access point to replace a venerable WAP54G. It worked fine for both v4 and v6 in a basic config, but when I wanted to set up a guest SSID the problems started. SSIDs on a VLAN didn't support v6 at all and the v6 router announcements on the default (untagged) VLAN1 leaked into the guest SSID(!). In correspondence with TP-Link they said this device would never support v6. Luckily there is a OpenWRT build for this device, so reflashing and configuring and I now have fully working v4 and v6 on both main SSID and guest SSID. Thanks OpenWRT and a raspberry to TP-Link!