I think that depends on how warm, or not, you personally sleep. I took two silk bag liners, and put a smallish piece (should have been larger, but it's what i had left over) of 2.5oz Climashield apex in between them, sewed it up, and took it out in 37 degree weather and was mostly fine except when the wind blew hard--i was sleeping in an AT shelter with a very open face and silk is quite breathable. I was also wearing a lite down 'sweater', a winter hat, a cashmere sweater, wind pants and silk weight polartec powerdry base layer bottoms, and some merino wool liner gloves. I used the BAIAC pad also.
If i was using your set up, i think i would be warm down to high 20's or so. I would say on average i'm a moderately warm sleeper.
But that can vary from time to time even with the individual. Many things can affect that.
Btw, silk is pretty warm stuff for the weight, because of it's combination of being very fine and small diameter fibers, somewhat triangular shaped (yes the shape of the fibers can affect how much air it traps, just as the fineness or if it's hollow or not), and being animal protein (naturally insulating).
But if you can find a liner that is made out of somewhat densely woven, polyester microfiber, that might add a bit more warmth than the silk, but be more durable. It would be easy, for example, to make yourself one out of something like Pertex Microlight--find a DWR free one to reduce weight.