Well, I'll share my recent experience with nearly the same yeast and style.
I just finished fermenting a hefe using
WLP300 which is the White Labs version of Wyeast 3068 (according to Brewing Classic Styles).
I fermented at 62*F also (well below the recommended 68*F for White Labs) from start to finish for 13 days. I pitched the equivalent of two packs of yeast via a starter and I oxygenated it for about a minute when I pitched.
The krausen was small. I was prepared for major blowoff but it didn't happen. It did smell like sulfur though. It went from 1.044 to 1.012 which is 73% ADF (on the low end of the range).
I am *really* happy with how it turned out though it is still young. It has more clove than banana but is so fresh and yummy. It reminds me of my first ever Hefe while sitting on a patio outside Cafe Journal in Heidelberg. Just magical. I might go up a degree or two the next time to see if I can get a tad more banana if it doesn't come through with age.
Regarding your case, I didn't take gravity readings along the way so I don't know where it was at the one week mark. I too would have *guessed* yours or mine would be mostly done in a week, but like I said I usually leave it alone and don't take a hydro reading until 10-14 days for ales. I would expect yours to drop to 1.011 to 1.013 based on the
attenuation range on Wyeasts site.
If I were you I wouldn't sweat it. I think I'd leave it in the basement and let it do its thing. If it is still giving off CO2 which is a byproduct of fermentation it is clearly still working. If you feel like you have to take action, you could bring it up out of the basement to warm it up some. That yeast is good up to 75*F and by starting at 62*F I don't think you would get undesireable flavors by finishing warmer. Let us know how it turns out.
