I’ve heard that it’s advisable to get a memory foam mattress topper as well as a nicely padded mattress pad. With those things on top of the regular mattress, will there be a need to get extra deep twin XL fitted sheets? Or is the regular mattress so thin that even with the “extras” a regular sheet will be fine?
I’m a first-time college mom here so any other insider information on what to buy (especially things you wouldn’t ordinarily get) would be very appreciated! 
Thanks!
That’s a good question. My daughter also asked about a memory foam topper. I think you could measure a regular depth twin if you have one at home and test it for yourself. The mattresses seem pretty standard depth. We just returned from orientation so I looked back at the photos and definitely seem standard depth.
I have a pretty thick mattress topper and my fitted sheet doesn’t cover the entire mattress vertically, but it’s hardly noticeable. You may have a hard time finding extra-long AND deep sheets, so I wouldn’t worry about it.
Bed Bath and Beyond has the extra deep one.
https://www.bedbathandbeyond.com/1/1/371220-wamsutta-620-egyptian-cotton-deep-pocket-twin-sheet-set-white.html