Updated with dimensions.

I have 2, both closets type versus cabinet, neither with drawers. If your comforters are thin, the drawers will work, but if they are down and puffy , it's going to be a struggle. I actually roll mine, and tie with ribbons. Takes up less room and 'stay' better than if folded.

If you're going to use it as a linen closet, you may want to consider making the upper portion one large door, or double doors, so that you have use of the full width of shelves. The door(s) could have faux panels on the front if you want it to look like 4 small doors.
I suggest having one wide closet because I find that with sheets, extra pillows, large towels and misc. blankets that I need all the maneuvering room I can get.
Regarding the drawers:
I find the ones I use for long term storage are limited when it comes to actual usable space and accessibility. Whenever I need something that is on the bottom then I have to remove everything on top. Personally I prefer shelves where I can see everything and just pull out what I want. If you're only going to keep 1-2 blankets in the drawers then you should be fine.

Also, if you're going to keep the same door trim on the existing doors, check to see if the linen closet doors interfere with the upper trim.

I agree with both Annz and Patty Cakes' suggestions. I don't have a dedicated linen closet, but instead have built-in linen cabinets in our two main bathrooms. Neither have drawers, just shelves. But, I do have a similar set up to the one you've pictured, on one side of our guest room's walk-in closet that I'm using to store extra sheets, blankets and comforters. In there, my upper doors are double ones, making access to the shelves easy. But the drawers, deep as they are, are not working very well at all for storing my comforters in. I'm going to try Patty's roll & tie idea with them. instead. The drawers do hold sheet sets, neatly folded inside one pillow case fairly well, though. I can set them on end ( like books) in the drawers for easy access. The problem, up until Patty's idea, is that the comforters folded on the shelves are so puffy that my cabinet doors won't stay closed.

Anyhoo, just more food for thought. But, how wonderful to be getting ANY type of extra storage, so I'm happy for you! Don't forget to post After pics of us.
Lynn

Don't fill it in. It's there for a reason. Consider the problem of losing that area for maneuvering while carrying largish things up and down the stairs.

Fill the area with cardboard boxes and test it by taking a double bed headboard and box spring up the stairs, or a highboy.

Can you do it?

If not, install a tall linen cabinet that you can move out of there.

An excellent design point about the actual physical space -- and being able to use it to move items around and in-or-out of the adjoining rooms ....

Yes -- perhaps check into adding a basic armoire or vintage wardrobe to house linens .... or add basic shelves (with lined and labeled baskets to hold linens) that COULD be removed if things need to be moved around that area .....

Patty_cakes, good tip, thanks! I'm actually thinking smaller (say, twin size) comforters, for use when on sofas.

annz-upper portion is two tall doors. To be totally honest, other than the comforters/afghans, I'm really not too sure what I'll store here. Perhaps overflow shoe storage :)
I love your idea for keeping the sheet sets in a pillowcase; I go crazy hunting for certain sizes.

lazygardens, teacats - thanks for thinking of this, we have definitely taken that into consideration. We can come in at an angle from the family room and make it up. (We were carrying up 4x8 3/4 inch plywood sheets this weekend, could easily go wider).

edited to move color question to a new post.

This post was edited by oldbat2be on Wed, Jan 8, 14 at 6:28

fnmroberts - beautiful linen closet, I like seeing your organization.

Did you have this built for you or did you huy it?

I designed it in sketch-up, then ordered panels, drawers, drawer fronts from Conestoga to spec, then DH built it.

The one in the bathroom too? Thanks so so much, I think I know what to do now.

Debra Hochman - not certain whether your request was directed to the OP or perhaps my earlier reply. Nevertheless, the photo from fnmroberts is a custom build for our space. DH drew the concept for both the vanity and linen cabinet then we had a local cabinet maker build them to coordinate. Our previous linen closet was builder-grade wire shelving behind bi-fold doors. It was never very useful.