You can do it in Microsoft Publisher which is part of Microsoft Office. It's still a real faff but it's easier than trying to do it in Word.
You'll want each line of text to be a separate text box. Create one text box the width that you want. Put a single line of example text in but don't hit return at the end of the text. Select all the text in the text box then choose Text Box Tools from the menu. At the left of the ribbon you should see Text Fit. Choose Best Fit. That should then adjust the font size to stretch the text.
Then just copy the text box as many times as you need for all the lines of text and change the text in each box. By doing the formatting to the first text box before copying it will copy across the font style and best fit options so you don't have to apply it to each text box manually.
Not a regular user of any MS products, but a simple question for you Snorbs...
If you put a smaller number of characters into the phrase, does the font size force the depth of the box to increase automatically, or could it be that the different sizes on the original were created with 3/4 different size boxes, ie having different depths to cope with the fonts being larger/smaller ?
Struck me the original might have had say 4 different size boxes (then all 4 copied and pasted a few times, as the text sizes appear to be in similar order over and over) and then the text altered for each line to be unique content.