My main concern would be some late winter weather in the mountains (even if you have an SUV.)

Streets and Trips gives a 3340 mile route as follows:

From Miami on Florida Turnpike to I-75 northwest of Orlando

Proceeding on I-75 north to Chattanooga, Tennessee

Proceeding NW on I-24 until merge with I-57 in Illinois

Proceeding north on I-57 until merge with I-64 upstate

Proceeding west on I-64 until St. Louis

Proceeding west on I-70 until Kansas City

Proceeding north on I-29 until Route 2 (Nebraska City)

Proceeding west on Route 2 to I-80 in Lincoln

Proceeding northwest on I-80 until I-84 merge in Utah

Proceeding NW on I-84 until it crosses I-82 in Oregon

Proceeding N on I-82 until merge with I-90

Stay on I-90 until it empties right into downtown Seattle :)