A good question....Vermont has participated in all of golf's 120-125 year history in America, as Dorset Field Club claims to be one of the country's oldest courses. I believe their date of incorporation has been reported as 1886 (one 9 built in 1886, one 9 built in 1999!).
The state has a well known Travis history in Manchester with Ekwanok and Equinox.
There was also at least one Tillinghast course, called Marble Island, although it was much modified, and was sold off for housing within the last 5 years.
Ross made revisions to Woodstock CC, and designed Burlington CC.
I know I'm not directly answering the question, but with the long golf history and propensity for great architects of the period to visit Vermont, it would not surprise to see Mac/Raynor visiting the state. Ekwanok especially was (and is) an old-money club that must have had several well-connected members who were backing the construction of golf courses in the first quarter of the 20th century.
A probable connection is Raynor's relationship with Ralph Barton (initially a professor at Dartmouth), or perhaps a competition/connection with Travis?
There is at least one abandoned course on the west shoulder of route 30 between Middlebury and Manchester. It was a 9-holer (I think) with a small shack as a clubhouse/pro shop (still standing, but leaning) and the course features are easily distinguishable in the farmland. When driving by in the late afternoon through the valley, with the gentle sloping former course laid out in front of you down to a creek at the bottom of the property....it's easy to dream of buying the land and mowing the grass once again...
I can't say I know of a course that exists today that could be a Mac/Raynor, but Vermont is certainly under-developed enough that it still may remain in a field somewhere.
EDIT: After giving it more thought, I seem to remember reading someplace that Seth Raynor was the original designer of Burlington CC. I remember thinking it unique that a course was worked on by both he and Ross, albeit at different times. I think the only reference I've seen to that effect was in Bob Labbance's Vermont Golf Courses book, circa 1990. The BCC website gives 1924 for the course's construction, whereas the DRS list says "new course" built in 1930.
I've played BCC earlier this year, and can't speak to Mac/Raynor features beyond a nice reverse redan at #3. The layout was pretty good, although seemed like it had been "Cornished" or "Hurdzaned" in recent years.