I would take Hwy 41 south to Oconto. Then take Hwy 22 west to Cecil (just east of Shawano). Then south on 117 to Bonduel (about 10 miles) to Hwy 29. 29 is a very good 4 lane highway. Take 29 west to Wausau. There catch I- 39 south to Hwy 21 near Richfield. Then west to I-94. South on 94 maybe 20 miles is I-90. Not the most direct but will get you there. The only traffic will be around Wausau. There is a low bridge on 117 before Bonduel. Not sure of height. If height is a problem stay on 22 to Shawano and pick up 29 on the south side of town by taking 55 south just as you enter town (there's a stoplight).