Great question, but check my #10, the answer is there: "Multi-cluster virtual warehouses help process multiple queries in parallel. One single query is always processed by one single warehouse, and only the size matters here, not the number of clusters. A complex query could benefit from a virtual warehouse with large size. A larger number of clusters do not matter in this case."

So NO, a query cannot run or be processed in more than one cluster, or more than one single warehouse.