I’m thinking full size blankets/comforter might have more use after college…thoughts from the experts? I plan on getting the bedding, kid’s getting the rest.
Get full if you want it to hang down and possibly cover things stored under the bed.
Most comforters are full/queen, so they are going to be basically double size. It’s your choice. Regular twin size blankets work fine too. The XL is just 5 inches longer, so a regular twin, which is long enough to tuck in at the bottom and cover all the way to the pillow area, might just be a little shorter by the pillows. My daughter even used her regular sheets - they were just really tight.
My own personal experience was that all bedding got tossed the second each kid graduated. If it lasts four years, it has already lived an overly “full” life, and nobody wants to keep any of it.
I.think a full/queen would be too wide across and would likely end up dragging on dirty/dusty floors. I’d get an inexpensive twin quilt and plan on getting rid of it after graduation. Some colleges put out bins where people can put in things that are no longer needed.after.college.graduation and they arrange to donate the stuff to a charity.
My kids used a full size comforter for college and a few years afterward. Sheets were XL though.
My D used a twin size comforter. It was 68x86 inches and plenty big for the XL twin bed (39x80). She stayed on campus for three years and moves off campus next year. She will need a bed so we are getting a queen size and new bedding for it.
The twin comforter is still perfectly fine so her brother is going to use it at college next year.
It is plain white and she had a duvet cover for it. I already have one for him that he can use, and just bought him some gray XL twin sheets.
My kids upgraded to full size mattresses as soon as they could - when they got singles on campus even before moving off campus or graduating. I’d definitely consider a full size comforter if you foresee your child wanting to move off campus or have a larger bed in on campus housing after a year or two.
All 3 of mine intentionally purchased a full/queen size comforter. They stored things under their beds and often had risers; the larger size fell down longer on the sids, hiding some of the things they were storing. They would all agree that it was the best way to go for them.
And I also agree with what @doschicos said in that they all moved off campus at some point and had a full size bed. No need to buy a new comforter.
Yeah, they are pretty “lived in” by the time kids graduate. I think my youngest one kept a blanket that I sent her freshman year when she said her room was a little cold – just a cotton one from Target that was $20. It went in a box and went to grad school with her. But all the rest (sheets, comforter, etc) didn’t. Don’t spend a fortune on dorm room bedding to start with – there is decent bedding in between the ultra cheap (and scratchy) stuff sold in the flyers that come from the colleges, and high end websites/stores.
Given how often college student wash their linens, those sheets and comforters should never come home! 
Honestly, my kids bedding lasted through 4 years of boarding school and 2 years of college no problem, until they upgraded to full-size beds. Still have some of the stuff and it’s in fine shape. Very good quality but Marshall’s or on sale prices. I’ll admit we’re picky about thread count.
XL Sheets and Full blankets to cover stuff under the bed. DD LOVED her bedding, and kept it for three years after graduation. We’re sad that it is gone! D2 just picked hers - all white. I tried to explain that you LIVE on this bed, bring in dirt and mud, etc. She insisted. I’m guessing we will be replacing before too long, but I suppose it’s cheaper to learn now then when she decides on white carpet in her first house…
I’d tell a kid who insists on white that future sets needed in college are on their dime.
DD got a duvet cover with a coordinating coverlet, the duvet cover was mainly white and has been replaced several times, the coverlet lives on and is well loved. They were both queen sized when we bought them for her dorm bed, in 1999. It was only Company Store, so not super pricey, but she loved that coverlet and still has it. I also still have the Company Store cotton blanket we got her (queen, but it shrank) at the same time.
Like @eastcoascrazy’s kid, my S tossed much of his bedding after 4 years of dorm living. I’m not sure I would think about lifetime use. Even D who believes the power of laundry never wanted to sleep on her bedding again, but did keep the quilt for future use as a picnic blanket type resource.
Two of mine wanted/used twin XL comforters while one wanted/used a full/Queen. It was personal preference for each one. The oversized comforter looked fine on the lofted bed.
^^ Good point about the lofted bed. And it would be very problematic for a top bunk…
My son used a full sized comforter because he had his bed in risers and it concealed his underbed storage.
Both my kids used the same xl twin sheets (S handed it down to D) and I think donated or tossed them when they were done with it.
Both got their own regular twin comforter. I think they kept same comforter awhile after they upgraded to full beds in apartments. Eventually, S acquired nicer bedding on his own done after he started his career.
None of us thought college bedding was forever, but always got 100% cotton sheets for comfort.