I went through the tutorial you provided and came up with a workaround.
Import your movie, delete the audio track and add the Speed Control effect strip. Set the end frame of your original strip to the resolution of your final image, in this case its 200.
Render the sequence. You will get 200 .png files
In the compositing workspace, import the image files as image strip and set up the node group as instructed in the video you provided.
Duplicate the node group and make a new copy of it. In the duplicated node group, change the offset to 1 and plug both node groups into an Alpha Over node. Control the Alpha Over Fac with the Translate node from the tutorial.
Hit F12 to render a single image. Open the said image from an Image Sequence node and plug the image output to the first Image slot of the previous Alpha Over node.
Change the Current Frame to 2. You should see a preview of your second render in the Viewer node. As of right now, there is only one image in the Image node. Change it to an Image Sequence and set the Offset to -1. This will allow compositing using the rendered images. Set Frames to the resolution of your final image. Render the sequence.
OPTIONAL. Save the final .exr to whichever format you prefer using a File Output node.