C5 and M5 are now supported in N.California and London

M5 and C5 Instances, the current generation of the Amazon EC2 General Purpose compute and Amazon EC2 Compute Optimized instances accordingly, offer a balance of computing, memory, storage and networking resources for a broad range of customer workloads.

Starting today, M5 and C5 instances are available via Spotinst in N. California and London regions.
We highly recommend our customers to add these instance types to their selection where applicable for better performances and cost savings.