That would be an issue as checked and my BU of iso is 2.7gb.. Don't know your options are maybe a friend could dl it for you. Nicer to try first as your system might have different hardware, drivers etc that an issue would show up in try method. MATE is excellent.
Another option might be to search for purchase copies similar to here:
Note: Older post did not spend time searching for newer.
https://ubuntu-mate.community/t/buy-ubuntu-mate-on-usb-flash-or-dvd/23390 Edit may be problem with this link on forum
Edit new link looks like there is extra characters (copied pasted) IDK
Have to click on Buy ubuntu mate on USB flash of DVD? link not the https://ubuntu-mate.org one.