Sportweight sub

I want to make the Squirrel and Oak mittens from HelloYarn. The pattern calls for Dale of Norway Hauk, which I believe is a sportweight yarn. The pattern calls for a gauge of 6 sts/inch.

Since I have a limited choice of yarns here, I was wondering: Could I substitute a sockweight (Regia 4-fädig)? I can obtain the above gauge with this yarn, but the fabric will probably be less dense. Would the mittens still be sufficiently warm?

What do you think? Thanks in advance.

I would just do a small swatch and see what you think. If the fabric is pretty airy might not be the best choice for a mitten. From Ravelry:
Adrian says, “I’m thinking the best way to change the size would be to knit these in different yarn weights. 8 sts. per inch (fingering weight) would make one 6” around and 5 sts. per inch (worsted weight) would do 9.5" around, etc. "

So if your hand is 6" maybe this isn’t a problem?