https://news.harvard.edu/gazette/story/2019/02/tracking-love-among-the-ivies/
Huh, I assumed because the Ivy League plays D1 b-ball and soccer that they were in the FBS. Learned something new today. 
All schools in D1 play D1 for all sports (unless Club). Within D1 there are two divisions for football.
I’m still convinced OP is a plant to drive CC discussion. The post history is full of threads started with vague and open-ended questions like this one.
Yep.
Smart Alec
LOL!!! CC needs to start compensating me.
They’re Famous! So they get put in the Top 20! So they’re famous! So they get put in the Top 20! So they’re famous! So they get put in the Top 20! So they’re famous…
Etc.
EDIT: Seriously, if the finest grain of your question/research is Ivy or Not Ivy then you’re not thinking very deeply and this answer should suffice. Ask a better question and get a better answer.
It seems questions doesn’t matter much, most internet posters lack intellectual depth and knowledge, they dutifully criticize every idea they don’t agree with and can only give crappy answers but once in a while, one can get helpful answers.
“Huh, I assumed because the Ivy League plays D1 b-ball and soccer that they were in the FBS. Learned something new today.”
There’s multiple layers within D1, all driven by football.
Lowest is FCS, where the Ivy and Patriot Leagues are.
Middle is lower tier FBS, which is where you find Rice (Conference USA) or Tulane (American Conference).
Top is FBS Power 5 Conferences (Stanford, NW, Vandy, Duke, ND). Which used to be called BCS football. Full monty football, and tend to be full monty for other sports too.
In D1 hoops, for example, everyone technically plays the same level and can make the NCAA tourney. But as a practical matter, you really only see Power 5 teams competing at the highest level. With a few exceptions (Gonzaga or Big East teams like Gtown and Villanova).
In the niche sports that don’t make money and game attendance often measures in the dozens or hundreds (baseball, lacrosse, soccer, etc.) the playing field is more level. So while the Power 5 schools still dominate, you do see more outliers – like the Ivies in lax and ice hockey.
re: # 28, Cornell men’s hockey home game attendance statistics are here :
http://www.hockeydb.com/nhl-attendance/att_graph.php?tmi=5347
It’s rink’s stated seating capacity is 4,267.
The game attendance for the hockey games it’s played at Madison Square Garden in recent years are:
-sold out (18,200)
-sold out
-sold out
-sold out
-15,027
-“14,000+”
Not sure why there aren’t stats for the late 80s/early 90s but I can tell you that we had to sleep out under the bleachers at the football stadium to wait in line for Cornell season hockey tickets because the stadium sold out. 
Thanks for this topic. Very fascinating discussion.