While I haven't used Protractor, generally when I come across an issue like this I use a scrollToscrollTo
or scrollIntoView() action to bring the viewport into view of the element.
Some cursory research on Protractor shows there are a few examples out there including this one suggesting you wrap the scrollIntoView()scrollIntoView()
action in an executeScript method: https://stackoverflow.com/questions/39399477/protractor-scroll-into-view-not-working#comment66147579_39399892.
So in your case you should be able to locate the Next button within the DOM and then scroll it to within view.