We had a similar experience when we went to the DLH for breakfast on our last trip in June this year. We had our trip in March cancelled due to the snow and we were meant to be staying at DLH, we then had to rearrange our trip and due to the then current offers couldn't afford DLH again so went to SQL 3 months later and said we would have to do breakfast at DLH just to see what it was like there.
We joined the queue and then explained that we weren't staying here but wanted to pay for breakfast, I got my purse out & the CM asked if we were staying on site, then just shook her head and told us no need to pay!
We saved a fair bit of money as we're 2 adults, 5 children & 2 infant! It was a wonderful experience, totally different class of breakfast compared to the other hotels.