The Lowa Stirling GTX seems a good sturdy 3 season boot. Some reviews suggest it should be rated as a 3 to 4 season boot, however as this review below suggests, it's performance above the snowline doesn't really cut the mustard.
"The Lowa Stirling GTX has been available for a number of years and it’s often reviewed in Trail as a 3-season boot. However, like the Mammut Mount Trail XT, it has now been submitted by the manufacturer for inclusion in the 3-4 season category. It is made using a full leather upper with minimal stitching to increase durability, and there is a full rubber rand around the whole boot for even more durability. Inside there is a Gore-Tex waterproof lining so the upper offers plenty of protection. Underfoot there is a Vibram sole that is good for walking over rocky ground with a reasonable lug pattern for general traction in soft terrain. Use the Lowa Stirling GTX for 3-season hill and mountain walking and it is a reasonable option with plenty of support for the foot and a good grip for use below the snowline. But the toe box is quite soft on the top, which is not ideal with crampons. The lug pattern on some boots is a little better for tackling muddy soft snow and slush too. The toe-to-heel flex is softer than other B1 boots and so this is really better suited to use below the snow rather than on the snow."
As well as having a soft toe box, you would have to check the stiffness of the sole for reliable crampon use. I recall winter hiking with a friend who was confident that his stiff, Scandinavian leather boots would cope admirably with C1 crampons. They didn't and he was constantly re-adjusting his straps before realising that he'd bent his crampons connector plate.
Hope this helps EF.
