[not OP, but hey…] There’s no need for DHCP with IPv6. Clients choose the last 64 bits of an address randomly. The address space is huge — zero probability of a duplicate address.

The first 64 bits therefore identify the network. If your ISP routes a /60 to you then you get to split that into 16x /64s.

That’s probably fine, but the IETF recommendation is to dish out a /56 to small sites and give them a /48 if they ask for it. ISPs usually have multiple /32s at their disposal.

It’s not about number of available addresses or networks. The joy of IPv6 is the addresses are so wide you can bring back hierarchical addressing. No internal routing chicanery is needed.

If your site has 64 buildings then a /56 lets you assign a /62 to each, with 4x VLANs in each building eg for printers, guest net, phones, lighting, admin, with even a subnet for each business function in the building.