Thank you for the replies. I didn’t mean to imply 15-20 as a hard limit, more in the sense of tailoring your portfolio for the job you’re applying to (both in terms of skills shown and project scope) as opposed to just shoving the entirety of your work onto someone.
I was simply asking if it was inappropriate to, in addition to this tailor-made content, either link to a website if they did want to see more. I agree that chances are they won’t click on it and if you did a good job with the above-mentioned tailoring of what you show, they shouldn’t need to unless they’re trying to nitpick between 2 similarly qualified candidates.