This is effectively the way to do it.
Pierre
P.S. from the Moodle docs:
Embedded Answers (Cloze) question type page
Question rendering
The question answer INPUT HTML ELEMENT ( Short and Numerical) or SELECT HTML ELEMENT (multichoice) are normally displayed in-line with the text.
The size of INPUT HTML ELEMENT ( Short and Numerical) will be adjustable to the length of the longest answer (good or bad) + a random number (0 to 15% total length).(Pierre Pichet 15:37, 26 January 2008 (CST))
The size will adjust to the length of the student response when displayed in the grading and feedback process.
The size of the SELECT HTML ELEMENT (multichoice) adjusts itself automatically to the longest answer.