Welcome to the forum!
Yes, there is a way to do that. But you should be sure (or at least pretty sure) that you don't need to edit that path anymore. Because once you do this, editing that path is going to be a lot harder.
-- Select the path
-- Path menu > Stroke to Path
Notice when you did Stroke to Path, how it changed from being an open path with a stroke and no fill, to being a closed path with a fill and no stroke?
So now you can change the profile of the end of the path, by adjusting the 2 opposite corner nodes with the Node tool. There are probably a few different ways to accomplish moving those nodes, and making the top horizontal, without varying the width of the rest of the path. Do you need some hints for that? Or can you sort it out? I don't know your skill level.