Maybe back in the day. Today it would be like breaking into Langley to play with their computers.
I used to do it regularly(late 70's) on summer evenings, coming in under the fence by 13 tee, playing 13, 14, 11 from old members tee and 12)
Once played the entire back nine midday in the middle of summer(left my ball on 18 green and dropped in 10 fairway)
didn't see a soul
no cups, but I knew where the Sunday pins were
12 green was a favorite spot for night putting
as one could drive out to 10 tee at Augusta CC, 100 yards away.