Thanks for reaching out!
Unfortunately, at this time, we have very limited stock on hand in winter-specific boots, particularly with the specifications you are looking for. One brand that tends to have more room in the toe-box is Keen, however, we only have the Keen Revel IV High Polar Hiking Boots available in a size 5. You may also have luck with Merrell, which tend to be a bit more roomy. Check out the Merrell Bravada Knit Polar Waterproof Boots or the Merrell Thermo Aurora 2 Mid Shell Waterproof Boots.
Depending on the conditions you are facing, you may be able to work with a waterproof hiking boot and a thicker sock in the winter. Here are a couple of options if you'd like to consider that route:
Hopefully this helps, thanks!
I have a similar need. You definitely want the right footwear. However, don't overlook the types and styles of socks you use, and make sure you have them to try on your new boots. Also, there are variations in boot lacing patterns that can provide short term or situational relief. Window Lacing and Toe Relief Lacing come to mind.