This is absolutely untrue. Grazing leases are accessible only with permission year round. Whether cattle are present or not. Cattle also don't need to be off leases by the first of november. The date for that is set in the usage plan the rancher submits with his lease renewals.
What you are referring to are grazing leases in Alberta, which have a November cut off date and allow hunting without permission. Grazing leases in BC are different.