Depends, are you only getting a /48, or can they statically route it through an IPv6 point-to-point allocation? If the former, not much you can do other than configure every host inside the /48.
If statically routed, and you have either a router or layer3 switch with IPv6 support, you can then statically route /64 allocations out of the /48, to each vlan or a port. Also if these are machines that only need a single IP to start, and you don't really have a l3 switch, then on a router you can carve a /64 out of that /48, and use RA + autoconfiguration and let the hosts automatically configure the last 64bits of their address (FFFE + MAC). Or don't use RA and simply manually configure the IPv6 addresses on the servers, and increment in whatever numbering policy you decide on.
Remember, it is a lot of IPs, and generally you get a /48 when you need multiple subnets. If you run a flat network with no routing and mostly layer2, and didn't really need 65536 /64s (subnets), you'd probably be fine with a /64 and the colo providing gateway.