You say Nashville doesn't need Freddie, but sure the Leafs don't need Saros. And even Granlund though a nice addition isn't needed either.

Leafs would then lose Saros or Campbell to Seattle.

Better idea is to go for Fabbro

Granlund would be very helpful. Solidifies the top-6/9 and gives them more balance. I think he helps Tavares and Nylander a lot more than Vesey, Simmonds, or Mikheyev have so far. He might not be desperately needed, but it would be great to upgrade the roster and this accomplishes that.

Saros is having a tough year (as is everyone in Nashville) but his careers stats have been equal to slightly better than Andersen. He's also younger, and cheaper. I think he turns into a great tandem with Campbell until Woll/Scott are ready, or that combo could be good long-term if neither one works out. I think it's better plan in the crease then what they have right now, which is...... re-sign Freddie?

What would you do with the goaltending, short and long-term?

Maybe. I honestly think it's more likely they lose a defenceman.

Fabbro hasn't had great results as an NHLer and the Leafs currently have nowhere to play him. Justin Holl has been better this season and last than Fabbro, you're not going to make the team worse. Plus Fabbro is going to cost a lot, and it's probably not a price the Leafs will want to play for a guy who isn't in their top-4.

If they trade for Saros, you almost guarantee they lose one of them.

& Fabbro has been fine. He's also been on a terrible team. He's shown he can handle top 4 mins at such a young age which is valuable. Definitely wouldn't mind giving up a prospect and a pick for him

I think NSH accepts that, at TDL.

If Seattle takes Jack Campbell, I think the Leafs brass would be fine with that TBH. But I think teams like Arizona, maybe Detroit or Chicago, even Montreal, Ottawa, potentially Pittsburgh or Winnipeg have better or comparable options to Campbell, so I don't think it's a for sure that Toronto would lose a goalie, considering Seattle will only take 3-4.

What would you prefer the Leafs do with their goaltending? Sign Freddie again?

Ryminster27 makes a great point, good chance that the either Saros or Campbell would be lost to Seattle.
Don't know what the Leafs are going to do next season. Sure the Leafs don't either. But lots of goalies will be available via trade.
But the Leafs aren't trading Freddie this season, especially with the 2 week Covid restrictions.
The Leafs keep Freddie and there is no cap room for addlitional forwards.