On the ordinary Wix-Editor you do not have that much possibilities, but there are maybe quite different WORKAROUNDS.
Maybe this post can help you out…
Or you use another technique called → READ-MORE
In this case you set a fixed length of characters which can be added to each of repeater-items.
Those which have a bigger length of used characters in the description, those will be cropped → that means after the character-limit was reached —> … ← dots at the end of the text will be added and a READ-MORE-BUTTON occurs.
This way → all your REPEATER-ITEMS will have the same description-lenght (always same amount of CHARACTERS).