Did this used to be a Hertz location? (Or was National always in there somewhere too?) I spent a week at this hotel and I'm distinctly remember using Hertz free days at the property, precisely because there was no free parking at the hotel and no easy/safe/legal free street parking near it. In any case, I was successful then: morning pickups, late-evening drop-offs (after hours for the location), no parking or other fees.

Unless the hotel changed its processes, it would still seem possible with National. I don't ever recall wanting/needing in & out privileges, so that wasn't an issue.