I ordered the moccasin a half size smaller than my boots. I think this worked out well for me. I know that I wouldn't want them any smaller and don't feel they need to be larger.

The Shearling Oneida is the perfect slipper for cold weather. It's warm, comfortable and, with its bullhide molded sole, fit for a trip to the mailbox to fetch the morning paper (unless there's a lot of snow on the ground). It also fits true-to-size.
It's not cheap, but it's excellent value for money.

Super warm and comfortable. Hand made excellence! Would love an ankle high option!

They are like walking in a cloud. Never get too warm and let your feet breath. Also use them to walk the dog. Everyone should have a pair and use them as sleepers and fort short walks.

As usual, excellent design and execution of these comfortable, warm slippers. While I'm sure they would hold up with light outdoor wear, I don't dare step outside to preserve their soles for the rest of my life. Sizing tool is absolutely correct - order one full size smaller than your normal sizing. Yes, they are expensive, but probably the best made, most wearable, and comfortable slippers anywhere on earth.