Would, have, whatever.
Heck, it was a black tie wedding and I was wearing a wrap front dress that the bride helped me pick out knowing
that I'd need to nurse. I just slung a burp rag over my shoulder to cover my breast down to ds's face (not over his head, ew), and went at it. Noone said a word, except my own mother, who was mortified, but I take her opinion on it with a grain of salt since she never nursed longer than 2-3 wks. It may have helped that the groom and some of the guests were doctors (surgeons mostly), so seeing a woman NIP was the least graphic thing they'd seen in awhile, but there were plenty of people who weren't.
Now, the one and only time I ever "hid" to nurse was the time I was a bridesmaid. You know how those dresses are.
: I had to unzip it halfway down the back and darn near remove my strapless bra. THAT was a little too much exposure for my comfort.
Luckily ds was over a year old and happy to be put off with a sippy of water and some goodies from the buffet and only insisted on nursing once during the reception.
So yeah, bring a sling or put a blanket over your shoulder if you feel like it. Heck, go sit in a corner if it makes you comfortable. But if your ds isn't used to bottles, he's likely to just get fussy, which is way more disruptive to a wedding than NIP.