GL: Current on the Mississippi River

[Tom Felice]

Hi,

I'm planning to take my sailboat from the Cumberland River to Lake Michigan.  I'm concerned about the portion that I'll be on the Mississippi going upstream.  The boat is 30ft and it draws 5ft.  It has a Yanmar 2GM rated at 15hp.  In flat water it will push the boat at 6 or 6.25 mph easily at my comfortable RPM range, about 2100.  

Will I be able to make way in the river current to where I have to turn off for Chicago?

I need to have my mast taken down for bridges that occur after the Mississippi.  I can take the mast down more easily in Kentucky.  However, should I consider leaving my mast up to get use of my sails going against the current, then taking them down after I turn off?

I have heard, but not sure if it is true, that current is less powerful at night.  Is that true and if I have good electronic and paper charts and lights should I consider to steam at night?

Is one side or the other of the Mississippi having a slower current?

I have heard of the many bars on the river so running off channel is out of the question, to get slower current.

What should I plan on for velocity made good so I can plan my time?

Thank you,
Tom Felice
tafelice at yahoo.com