Back when we had a S&B, we had many items like TV's, computers, etc. held for pickup at the UPS office. We addressed it just like you mention. Now this was almost 10 years ago but I can't imagine it has changed.
p.s. Just wondering why UPS won't deliver to the state campground. A friend of mine has his arm shipped to the park office via UPS, no problem.
Donna & Don Full-timing across the USA for over 7 years and still loving it!
2016 Augusta Ambition 38RL
2016 RAM 3500 Laramie DRW