Is there a printer that can scan 35mm film slides and print them the size you want? If so, can you please name a few?

I would have said no, but the video is certainly proof of Yes.

Notice that this is not a direct answer to the question - the process of scanning is separate from the printing - the work is done on the computer using either the software that comes with the printer or other scanning & editing software. You don't lay the slide down and make choices on the printer and a print comes out, you make the choices on your computer.

My answer would have been to refer to the Epson Perfection V500 Photo scanner which I bought for under $150 a couple of years ago and have used for some jobs but not everything I planned to. I bought it to scan 2.25x2.25 (Medium) negatives and color slides which it does at high enough resolution to bring out small details but the higher resolution scanning is very slow, you really have to have something else to do while working through a stack, etc.

As an indication of possible results (not great or pushed) at this link http://mikegigi.com/firthg/louise.htm#PAINTINGS are scans of a painting I thought lost in a fire (along with a recent photograph proving it was not) where the painting was about 1/2"x3/4" in the print, negative, or slide put into the scanner.

Not directly... you must scan the slides first, then you can send them to the printer. At least I know of none that can do it in a single step.

Once you have the transparency scanned, depending on the quality of the original image and the quality of the scan, you can print it at any size you want. If you have a crappy image to begin with, then not so much. If your slide is well focused and exposed, then billboards are possible easily.

You can buy a negative scanner that will make a digital image of it . I bought one for around $125 that works quite well . It puts the images on a SDHC memory card .

Mine will also scan 35mm negatives and 4" x 6" as well as 5" x7" prints .

https://www.youtube.com/watch?v=LO4X6vAtIxU

no