My 1995 Windstar has 215,000 miles on it. Manual calls for 5W-30 oil whichI have used during its lifetime. Motor is still running good. Uses about a 3/4 quart in 5,000 miles. I remember reading a recommendation over a year ago (it may have been on this forum) that it would be OK to go to 10W-30 with that many miles. I live in southeast Minnesota. Any suggestions?

If it were my vehicle, I would not go to a thicker oil right now.....the cold time of year.
3/4 quart in 5K miles is not something to worry about.
Also....give the bottom of the motor a looking at......if you see any sign of dampness.....oil leakage.....that could be a major part of the oil usage.

FORD issued a TSB saying that 5W-20 is recommended for our Windstars.....which is what I have been using.
The 5W-30 is still fine.....but at this point I see no need to go to a 10W-30 based upon your situation.
My windstar is a '96 3.8L with 204K miles on it.