A resolution to the Sarah Jane Smith:Dreamland release.

maybe it could be done as a Short Trip especially if they had the Doctor involved in her rescue
It may be hard to fit it in another range (at least of the current ranges - [could they fit it in a New Doctor Chronicle?])
Now, if they were to do a set of stories featuring the cast of SJA then they could have 1 story in which K9 gives an account of what happened to her
I believe it is too soon for a recasting

It's pretty divorced from it. A Girl's Best Friend is two decades in the past by the time of the SJS series; give or take, a dating controversy or two. However, there is a thematic link of sorts in the antagonistic cultists who are propelling events -- they were formed out of the Brotherhood of Demnos from The Masque of Mandragora.

There is a tale covering Sarah's rescue from the shuttle, but it's a short story, so never mind then. Suffice to say, the Ninth Doctor finds and takes her home.

I would.like to hear a story covering tue resolution of this, ending with our heroine moving into Bannerman Road.

A Stephen Critchlow short trip is probably the best option, but if the Doctor saves her he'll have to stay behind the scenes so that she can still say in School Reunion that he never came back for her.

Well for starters there are the resolutions that I fully expect Big Finish will provide such as the endings of...

Jago & Litefoot series 13
Doom Coalition 4, and
Charlotte Pollard

And then there are those that I am not sure we will ever get. My current top three in reverse order would be...

3, the ending of The Daleks Among Us

2, the ending of The Sacrifice of Sherlock Holmes

1, the ending of The Well Mannered War

A sequel to Real Time would be perfect for short trips, narrated by Colin. Likewise, a story where Sarah Jane was rescued by The Master, for his own nefarious purposes, which she would of course ultimately foil, could either be a regular, or a subscriber exclusive short trip. If the former, hire Beevers to narrate it, and if the latter, it could also be made available to anyone who has purchased Dreamland and has it in their accounts. And given that everything after Sarah Jane gets rescued would be a new story, it wouldn't be as new listener unfriendly as it might at first appear. Instead it could make a lovely little bridging piece between Big Finish's Sarah Jane and her TV return to the role.

Given that Big Finish still sells those old releases, and even actively pushes them occasionally in sales, and given that it was Big Finish that left these unresolved, I just feel like they kind of owe some kind of resolutions to their customer base. And while in practical terms I don't expect them to spend significant time and money to do so, short trip releases seem like the perfect low cost, practically no risk solution.

The Well Mannered War, on the other hand, could surely sustain a proper, full cast sequel, either as part of the regular FDA series (the first episode or two of a new Romana and K-9 season), or some sort of special release.

I would not mind some kind of Short Trip style story to put a button on the end of the SJS audio series. (I consider the SJS audios and the TV series to be separate canon)

I've probably mentioned it before, but on my own copy of Dreamland, I edited the ending,  inserting a song that I thought appropriate after Sarah's last transmission dissolves into static. I figured this was the only kind of closure I was likely to get there.  

Do tell?

The Doctor bypassed it so often that it was practically useless at deterring the Black Guardian. The Black Guardian himself lampshades this fact in Casualties of Time.

I believe there was a line about broken electronics in a box being stolen and Sarah said the the parts didn't exist yet. I took this as implied to be K9. Also fits with School Reunion where K9 is broken down.
So definitely takes place after Girls Best Friend.