Fermenting time for small batch size

Hello,

I brewed a 1.5-gallon batch of a strong brown ale two days ago and I was wondering how long I should expect it to take to ferment. I am use to brewing 5-gallon batches, so I am not sure if the timing is any different for smaller scale batches. I used about 70-80% of a vile of white labs English ale yeast. The airlock is bubbling a lot more than I thought it would, because I am fermenting in a 3-gallon jug, so there is a lot of headroom. Finally, the OG reading was about 1.080.

With that information, how long should I expect fermentation to last?

It will take about the same amount of time. The yeast propagate to a certain density, regardless of container size.