if it’s 300 dpi then you’re good for print… in indesign you can click the ‘info’ panel and it’ll tell you what the actual ppi and effective ppi is. If effective ppi is 300 ppi you’re good. but once you enlarge the picture the effective ppi will go down. even if it goes to say 240 ppi you should be ok esp as it’s not the main focus of the ad…
otherwise if i needed it bigger, i would enlarge it slowly slowly in photoshop whilst keep checking it’s looking good.
if you do overprint view or a press quality pdf you’ll also see if it’s looking blurry or not