You could deploy and balance your workload across multiple zones and
regions to reduce the likelihood of an outage and have access to multiple
resource pools when you need to expand quickly. Please review this
documentation which outlines how to build resilient and scalable
architectures on Google Cloud Platform.
You are able to create a reservation with Committed use discounts to reserve Compute Engine zonal resources, to ensure resources are available for your workloads when you need them. There are limitations and restrictions you have to know before you create it. You also can file a public issue tracker to see if there's an outage versus a regular stockout.