It looks like we won't get any more R5's in large volumes until the end of October at the earliest.
From B&H Photo:
In our last email, we shared that Canon R5 preorders were very strong and Canon’s deliveries to US retailers have been extremely limited. We also promised to send regular updates. Since that note, we received an updated shipment schedule from Canon. Based on this latest information from Canon, we expect to ship your order before the end of October. Please note that this information could change if Canon updates its schedule.