I pretty much second what Mike said. I've done plenty of winter hiking in boots similar to these in stature (La Sportiva Makalu II), and been fine, but for probably each hike they've been fine for, I've had really cold feet on another hike. It all depends on the conditions. What I find with non-plastic boots is that snow can accumulate along the top of the boot and over the tongue, especially if crampon or snowshoe straps are wrapped around the boot, and that can chill the toes. Plus, they're not perfectly waterproof.
That said, I wore my leathers to climb
Washington three weeks ago, as well as
Franconia Ridge two weeks ago, and found that up high on rime and crust my toes were warm and my feet fine. It was only at the middle elevations in the soft snow that my toes were cold and numb due to the snow sticking to the boots.
As for more technical aspects, they do appear that they'd be fine with strap-in crampons, which are adequate for most of the winter hiking trails in the Whites.
The typical plastic arguments are:
Overnighting: pop the liners out and keep them in your sleeping bag with you overnight, and you're ready to go in the morning.
Waterproof: plastics are 100%.
Insulation: plastic liners tend to be very, very insulating.
The other side of the argument is that plastics are heavier, can be more work to hike in, and are downright uncomfortable if the lower elevations are devoid of snow.
So it all boils down to what you really want to do with these boots. I'd suggest you head up north and try a shorter hike with them and see how your feet and toes do. Do something like Tecumseh, or head up to Lonesome Lake and then wander up Fishin' Jimmy to see how you fare in the wet. Give them a trial; if they're cold now, you'll definitely want something insulated later.