Yeah its definitely pretty easy if you are patient, take your time and get there early....really early. Last year I did almost bust a hen though due to a full moon and 4" of snow on the ground. She putted a few times so I stood still for 10 minutes and waited for the moon to co behind a cloud before I moved again.
My issue isn't getting under the roost, it's getting to where the birds want to pitch down. Seems that even if I sneak in and set my decoys up where they usually pitch down, they decide to fly a different direction most days.