Size of text field

Does your theme have a Custom CSS Section?
If so, you can input this:

textarea#order_comments {
height: 277px;
}

Just change “277px” to anything you want.

If your theme does not have this option, you can download WooCommerce Checkout Manager Pro which has this option.

That doesn’t work …
I found a way to make the box bigger:
.wccs-field-class {
width: 100%;
margin-bottom: 2%;
}
#myfld1.input-text {
height: 277px;
text-align: start;
}

BUT the text does not wrap inside the box, like it does on the “Order Notes” text box

Simply because the field you have created is a Input Text box, which is different from a Text Area box. The only textarea box i see on the screenshot is the order comments, hence the reason why for the code above.

You would need to create a Text Area box, to get the text to wrap.