I have travelled between NE and WI many times ... I grew up in Nebraska and have a permanent residence in WI.
1) I suggest you cross the Missouri river at Sioux City (and follow the bypass around) and take US-75/IA-60 and MN-60 all the way to Mankato, MN
2) then take MN-60 east to Wabasha
3) Then WI-25 north to US-10 eastbound to Stevens Point, WI
4) At this point (because of lack of roads that cross this region between Stevens Point and Shawano) you will need to take I-39 north to near Wausau and then east on US-29 to Shawano
5) WI-22 will take you from Shawano to just south of Lena on US-141
NOTE #1: There is a famous spot in Osseo, WI on US-10 called Norski Nook ... they are famous for their home baked pie ... the strawberry rhubarb is my favorite ...
Note #2: US-8 is a more scenic route across Wisconsin ... but it takes you further north than Lena.
2004 Winnebago Journey 39W - 2012 Buick Enclave
Present @home Home: Oshkosh, WI
We call our rig "Ernie the Journey"