The traditional way of joining prints or negs to make a larger one is to print or shoot the neg with a little overlap, line them up side by side on a light table, tape them together at the edges, and use a straightedge and an X-acto knife to make one cut where the two images will butt together. With prints you might blacken the edges of the paper, if it’s a dark image, to keep the white edge of the paper from showing through, and then do some retouching to blend the edges as needed.
So with two digital negs, I think you could join them the same way, but you might have to retouch the print to blend the seam.
Why not try it with a small print to see how it works?