Yep, most barley wines I've seen were in the 9-13% range. For comparison, typical grape wine is roughly 12-16%, so similar territory in terms of the quantity it takes to get you sloshed.

Lower ABV is definitely better for all-day drinking, especially on a hot day when you need hydration too. e.g. Germans like their summer Radlers which are just lager mixed with lemon soda, often only ~3% ABV overall.