Am I missing something with Detroit? It has to be up there with the worst city to visit in the US unless you're some crazy die hard eminem fan.
Will also be freezing! Save your money, it's got to be the equivalent to a Feb five night break in Burnley!
I'm based in Boston and would stay clear until May time, it's absolutely baltic.
If you had the time, driving San Diego / LA to SF would be a nice trip - if yo haven't been the Big Sur is stunning (and flights are usually reasonable in Feb)
Otherwise New Orleans would be perfect for 5 days /...