For long trips on a diagonal I plan a "preferred" route then modify it to adjust to short term weather forecasts and reports of road conditions.
For example, past 35 years we've been doing winter trips (home for Christmas) to southern Michigan. The shortest fastest route is I-44 to St Louis, I-55 to I-80, then I-94 into Michigan. But day to day conditions can make some part of that unusable, and there are dozens of alternatives for different sections, like going I-35 north Through KC to DesMoines to get around problems in southern Missouri or central Illinois, or taking I-70 from St Louis to Indianapolis to avoid a storm in northern Illinois, I-70 to I-75 to go through Ohio because northern Indiana is messed up. I've even gotten as far as Chicago before diverting to I-80/90 toll roads to avoid a lake effect storm in western Michigan, and once went as far south as Memphis coming back home because everything further north was shut down west of I-57. A lot of times my strategy was to travel north-south behind a storm, delay driving through it, and certainly to avoid staying in the storm system to be running its full north-south length.
If I get off the Interstates to use the trunk highways, the number of alternate routes approach hundreds. We don't have the high density of Interstate routes you enjoy in the East, but our trunk highways tend to be almost as good and less heavily traveled.
For your trip I-90 out of Albert Lea is probably the fastest route, I-94 out of Chicago costs very little extra time (and connects back to 90 to cross all the western mountain ranges). Taking I-70 out of Indianapolis to Kansas City, then I-29 to connect with I-80 to Salt Lake City, then I-84 and I-82 into Washington adds about an hour to the trip (42 vs 41 hours driving time).
That's a choice of three Interstates across the northern plains, and two choices to cross the Rockies with little difference in travel time. You make your choices based on weather forecasts or known hazards (e.g. you don't want to cross North Dakota if the Red River is flooding, you don't want to use I-80 if there are late blizzards in Wyoming). All cross the Cascades on the same route, I don't know the weather risks for that; I think it is snow chains country.
There are three other Interstate crossings: I-80 crossing the Sierra Nevada into central California (reached from I-70 or I-80, two different Rockies crossings) or I-40 to Bakersfield and up I-5, or I-20/I-10 into Los Angeles. This most southern route has the least problems with winter weather but is at least a full day's extra driving. I-40 is usually through with winter by late March, and getting into the spring thunderstorm season. I-70 and I-80 can still have winter weather, which is why we watch the forecasts for travel.
Tom Test
Itasca Spirit 29B
