Wide Yeast Temperature Range

With my 2nd batch fermenting away, I was wondering what people made of the really wide range of temps for certain yeast strains?

I'm using Wyeast 1028 London Ale for this batch, which is a porter, and I noticed that Wyeast puts the temperature range at 60F-72F. Seems really odd to see such a wide range, especially one that goes up into the 70's!

I started fermenting at about 68, but have now brought it down to 65 over the course of the first 36 hours. Is this a very forgiving strain, or should I consider cooling it further?

Low 70's is a normal recommended limit for an ale yeast. Since you're making a porter, you'll be fine fermenting at 68-70, since complex, yeast-produced flavors are largely masked by the roasted malts and are even sometimes encouraged in small amounts.

If it's been at 65 for awhile, however, you'll want to just keep it there for the duration. Temperature stability/consistency will do more for you than trying to get smack dab in the middle of the recommended temperature range.