You know, no one really seems to consider the fact that Andromeda is a Black, and therefore distantly related to Harry.
Even in stories where the Malfoys get considered guardians suitable for Harry, no one brings up the Tonks', and the fact the also are related.
Perhaps the Potter and Malfoy lines crossed way back somewhere, or even the same of Black and Malfoy, giving the Malfoys a larger relation to Harry, the same could then be said of other purebloods. The Longbottoms. The Weasleys. The Prewits, which, by extension comes back to the Weasleys.
Literally any pureblood family, and probably most of the halfbloods, (even Snape, as a Prince) could claim very very very distant relation of some kind.
But I digress. My point being, for how beloved Tonks is, she and her family get forgotten when Harry's custody comes into question.
Imagine if Harry did get sent to the Tonks's, and he and Nymphadora discover he has the potential to be a metamorphmagus too! They truly become a family to Harry, and it's beautiful, because when little Teddy comes along, both parents agree, Harry is Godfather. Who better then Remus' last link to his friend who was like a brother to him, and the person Tonks views as her own little brother.
And can you imagine the Tonks' coming to the Triwizard last task? And Tonks and Fluer hit it off, and Tonks introduces her to Bill, and they still fall in love, but Molly is less opposed when Bill first brings Fluer around, especially since Tonks has been asking her advice about Lupin being all, 'he's not good enough for her, or really anyone'.
Tonks and Fluer and even Molly bonding!
Molly and Andi both becoming friends because Harry and Ron are friends, and Molly has been looking out for Harry since first year.
Ted just being the loveable guy he is! Probably teaches Harry wood carving or smthn, while Harry actually manages to impress both Andi and Ted with his cooking.
Harry opening up to Ted about everything with the Dursleys.
Just, Harry as a Tonks guys.