pushing in boots

What are the maximum/worst conditions that you would use the Tecnica gtx Cruisers for (ex. could I do winter ascents of 14ers in them, and if so, how much farther could I go?). I'm afraid I might push too far in a boot that isn't made for the terrain I am up aainst. I have tried them on and they fit me perfectly, which is a plus. thanks for the help.

the boots are at http://www.mgear.com/pages/product/product.asp?level1_id=6&level2_id=10&level3_id=6349&item=101831&level2_title=Men's+Footwear&level3_title=Mountaineering+Boots&N=0

I would call Mountain Gear and talk to them. I have found they are very straight-forward about the gear they sell. They do have an 800 number, so no cost to you. Personally, I would not use a boot with as much mesh as this one has for winter ascents - I have found they let water in too easily. On the other hand, the description emphasizes fitting crampons, so maybe it is more waterproof than most mesh-tops.