Gosh that’s a pretty project as it will impact the roofing and guttering, what about some updated landscaping and lighting?

I think the entry is nice as-is, though a new more modern door will take it up a notch (I like the one in your mock-up).

What is really needed here is landscaping to frame the walkway and entryway. Right now everything is off to one side, it looks unbalanced and the entryway is just hanging there.

I like your imagined idea, I would consider a new roof at the same time, to tie it all together.

More landscaping in the front of the window. Something that will bloom (hydrangeas, butterfly bush, etc) to balance out the heavier left side.

If you can swing it, I would remove the plain paving and install a more interesting driveway.

The proposed portico is of a different design language than the house and makes for an odd appendage. And will give you fits with the roof tie-in.

The house has a strong, simple, horizontality. At most I would add a substantial planter in the same stone as is on the house, if you wanted to direct attention to the front door. Other ideas would be as already mentioned with landscaping or a different pattern of sidewalk.

Expand my inspiration photo for the overhang. Looks like metal roof. Love the mix with the brick/stone of your home.

Stop while you are ahead. Your home looks great thus far. You've had a really nice hand on modernizing an older ranch. Push the envelope with more contemporary landscaping rather than butchering the roofline.

Get a black metal rail for along the walkway. Add high black metal planters on the left side of the walk towards the front door. Make a border in the areas marked with brown below. Learn about more contemporary landscaping for your climate. Add good exterior night lighting to your home so it pops at night.

I do not think the idea is wrong for the house but will involve a lot of work and money to get it right. I think you have been given some great ideas that all do not involve a roofline change. Sorry I do not love the brick and stone but on your house not bad .Love the walkway idea from redryder.. I love ranch style homes for the simplicity of roof angles and for sure not a whole new roof with too much height .A new front door can do wonders and some connection to a new garage door would be where I would start.