Double doors would be the wrong choice.

You can do the style you like in a single door with matching side lights.

I agree, with the others. No double doors. I like the doors you have and would look for some as close to those as you can get. Can the ones you have be repaired?

Actually, you don't have the space for a double door. It means that each door would be less than 30". Double doors are not as secure as a door with a dead bolt lock.

Would a six-panel door be the only choice or is there a different type of single door that may look more updated?

The door fits the house and the house fits the door. If you need a new front door, you could use a six panel or a four panel and they would be appropriate.

Other styles of doors will not really look as good, and updating a single element of an entire house really just tends to look out of place, because the house is still the style that it always has been--and there's nothing wrong with that.

This is probably the only alternative to the six panel:

Not sure what you mean by "updated"? You choose a style to work with the style of your home. You have a rather formal brick home in a vaguely Colonial style with built-up trim on a lot of the windows. Craftsman, Victorian, Louvered, Tudor, Barn door, etc. styles do not go with your home. You could paint the door a dramatic color and add solid brass hardware to spruce up a simple 6-panel door. Or get one with glass on the top panels.

Here are some beautiful entry doors on homes similar to yours:

Suburban DC - Cahill Residence · More Info

John Kimball Jr House (1730) · More Info

Exterior Arch Portico Front Entry · More Info

Exteriors | Facades · More Info

I also prefer the single wide door as more generous for wide people. It's unlikely you would open both doors to let in guests. To upgrade your exterior, when the time comes to replace windows, splurge for the ones with grills all the way through. So at this time, make sure your side lights have grills on the outside too. If you are not planning to stay in your home very long, don't bother; most people don't know the difference.

Curious why you recommend grills all the way through for windows. We are actually shopping for replacement windows :)

Without regard to aesthetics, I'd agree to the premise of opting against a double door. They are more susceptible to leaking air and water over time. The narrow opening as others have alluded to is another drawback here.

They are an upgrade that makes a huge difference in the perceived quality of the house. When you stand outside you can see your current windows have fake grills. Many do, especially new construction. This allows people to afford to buy the house. You have the option to upgrade or move. If you look around to see houses with real grills, you will see the difference. Here is Anderson's description:

https://www.andersenwindows.com/windows-and-doors/options-and-accessories/grilles/#grille-types

I got the full divided light, and it made my house go from piece of junk to class act. And my house isn't even as nice as yours. Yours would look amazing! You could even get the white since your house is all brick. White will save you money and help allow you to get the divided light. They tip in and are easy to clean from inside.

^^Wrong thread, but also "You have the option to upgrade or move"? So, if you have "fake grills" as you said, and you don't want to change out your windows, you have to move?

There is nothing wrong with the removable grills either. You can remove them to clean windows and put them back, and thats one huge advantage. My preference would be no grids at all, and if I bought a house with them, I would want them to be removable.

Haha.... absolutely not! @RoyHobbs but I can see now how someone might interpret my comment that way. OMG what a crazy view THAT would be. No, what I meant was that it seems the OP wants to upgrade this already beautiful home. I was suggesting that a better upgrade than a double door, which would be awkwardly narrow unless habitually opening both at once, would be to upgrade the windows with grills on the outside as well as inside. And @cat_ky you also are correct that there is nothing "wrong" with fake grills. Though, having had both, I find it easier for ME to clean windows with real grills. Supposedly it's easy to remove fake grills and wipe, but I did not find it easy to remove them I found it difficult and painful. Sometimes the tabs snapped off. And if I didn't remove them, stuff you stuck underneath the grill and it became dirty looking until I could remove them. The real grills windows easily tip in just like the fake ones, and I can easily clean each pane. It's easier for ME to clean several small panes than one big one. Maybe it's because I am short; I don't know. And the real grills look lots better from outside. That's why I recommended that as an upgrade instead of narrow double doors.