Managed it. The 32x8 LED matrix can now display temperature to one decimal point.
Making the digits just 5 dots wide enables more to be shown on the four 8x8 LEDs:
Another project on the Round Tuit pile for boxing up.
After running the display for a while I made a small adjustment, moving the decimal point to the bottom and reducing the degree symbol a tad:
The LEDs look white on photographs but they are actually bright red.
2 hours ago