Note that work has started on the culvert repair on Rte. 11 near Kewaydin Road. The entire road in that area will be closed October 6 though the 26th (more or less), and the NH DOT announcement, and detour route, can be seen here:
https://www.dot.nh.gov/news-and-medi...re-alton-44456
This route appears pretty circuitous, (perhaps to protect the neighborhoods?) but I think that you can probably get around the work area by using Rand Hill Road, depending on the exact locations of the road closure.
Thus, plan ahead, and allow for a lot of extra time on any east-west trip on Rts 11 going to, or coming from, Alton.