I have 800 gram rubber boots and can tell you I would rather have my uninsulated boots with good socks on. I wouldn't in any stretch say my feet sweat more than normal. I always sweat heavier from my head and back...my feet are normally one of the last places to sweat...however the lack of breathability kills my feet in rubber boots. My feet always come out of my rubber boots clammy. It wouldnt hurt to give boot covers a try. Maybe throw handwarmers in them before you hike out to the stand to warm them up. I would still change socks once I got to the stand though.No question part of my problem is the socks and Im sure with some of the walks I have to get to my spots there is some sweat too. Ive just been wearing a Darn Tough Micro Crew and they are snug. It's not always but sits under 30* where I am out there for 5, 6, 7+ hours I start fighting getting cold. I just figured I could try these booty things and not have to worry about anything else. It's not unbearable cold, but it's just the weak link on some of my hunts.
I also think a 1000 gram rating on a rubber boot will perform different than a 1000 gram rating on a pack boot. With where I am usually hunting a rubber boot is a must.