If you want to bypass Meredith...
 

I was just reading today that the bridge on the Center Harbor/New Hampton town line on Waukewan Road (apparently called the Snake River bridge) will be closing May 31 through Columbus Day. Folks who like to use Waukewan Road and Winona Road to bypass the Summer traffic mess in Meredith (like myself) are out of luck this Summer. Bummer...

Tues May 31 to Sun Oct 9, Lake Waukewan-Snake River Bridge closed for major repair
 

How's this for an alternate route with this Lake Waukewan-Snake River bridge closed?

Instead of exiting Route 93-north at Exit 23, go north one more exit to Route 93-north-Exit 24-Ashland; go right onto Route 25 through Ashland and Holderness to left onto Route 25-B, Dane Road into Center Harbor and onto Moultonborough, Center Harbor, or Meredith as a route to avoid the big intersection weekend snafu in Meredith.

That's certainly an option, but a much longer option than Waukewan and Winona Roads.

Just a correction to your post...When you take exit 24 you'd take route 3 through Ashland and Holderness, not route 25.

When you take exit 24 in Ashland.... it IS Route 3 and 25 off the Highway.

I do agree, however, with the secret route that you suggested

.... wrong! ...... sorry buddy! ...... Routes 3 & 25 co-exist and share the same NH state road from the big intersection in Meredith up to Tenney Mtn Hgwy in Plymouth where Rt 25 goes west past Walmart, and Rt 3 goes north past Forrest Howes' Auto Repair.

And, reg gas is 25-cents less expensive in Holderness, 4.499, at Golden Pond Country Store than in neighboring Ashland, 4.749, at Dead River Mobil. Plus, Golden Pond has golden quality coffee, pizza, fried chicken, and other food items ..... plus golden pond-uhs will do loon calls 'zactly like Katharine Hepburn!

.... imitating those loons .... https://www.youtube.com/watch?v=5yTwD7U_XV4

Is the Waukewan Bridge project complete?

Yes, I drove over it this morning.