I received IPv6 address space from an upstream LIR. Can I receive a /22 from the last /8?
Yes, if you have an IPv6 LIR-to-ISP allocation and you are a RIPE NCC member. No, if you have an IPv6 assignment.
See section 5.6 of “IPv4 Address Allocation and Assignment Policies for the RIPE NCC Service Region” for more information.