Using DNSMasq, how do I provide a single static route for an IPv6 network?

Assuming I am running two Dual stack IPv4/IPv6 networks:

  • Network 1: Internet connected
    • IPv4 – 192.0.2.0/24 provides a default route via 192.0.2.1
    • IPv6 – 2001:db8::0/64 provides a default route via 2001:db8::1
  • Network 2: Static assets
    • IPv4 – 198.51.100.0/24 provides a route via 198.51.100.1 to 203.0.113.0/24
    • IPv6 – 2001:db8:1::0/64 provides a route via 2001:db8:1::1 to 2001:db8:2::0/64

In a pure IPv4 network, the relevant stanzas in my dnsmasq.conf files for the two networks look like this:

# Network 1 IPv4
dhcp-range=192.0.2.2,192.0.2.254,2h
dhcp-option=option:router,192.0.2.1
# Network 2 IPv4
dhcp-range=198.51.100.2,198.51.100.254,2h
dhcp-option=option:router # Disables "default" route advert
dhcp-option=option:classless-static-route,203.0.113.0/24,198.51.100.1

I can configure my IPv6 network to provide these parts too, at least in Network 1, like this:

# Network 1 IPv6
dhcp-range=::2,::FFFF:FFFF:FFFF:FFFF,constructor:eth1,ra-names,slaac,2h
ra-enable

How can I define a single “static” route advertised over DHCPv6 (or similar), or is this not something I can do with IPv6?