Have you tested that drive base on the moat? Our initial pre-built concept chassis had a similar wheel spacing and we just got caught up. We thought the rock wall would give use the biggest problem, but the spacing of the moat can cause the chassis to sit on the moat ends and have the wheels free spinning. The rock wall was no problem. The moat was deceptively challenging for us. Our new prototype robot will have the wheels closer. Hopefully, our new spacing will be perfect and we can use that spacing for building the next two robots (practice and competition).
Here's our
video of this.