Free: Contests & Raffles.
The other option is an overboot where you hike in with the 200g boot and then slip those over if you are going to sit. My feet don't really sweat much, so I usually go with a heavier insulation. I don't sit all day in a treestand, if that is what you might do I would Google up and see how those guys deal with it.
I also have Nevada's with 200g. And Schnees pac boots. I do see at least 2 models on the Crispi website with 400g insulation. https://www.crispius.com/wild-rock-gtx-boot
I was doing a little bit of investigating on the kenetrics as well since I was trying to keep money going to a local place. I like the Crispi feed back though. I have a problem with wearing equipment out fast so quality is on my mind. 200g with a merino sock doesn’t sound bad either!