Was thinking something along the lines of this...
I get the JT Miller to Toronto sentiment from the Leafs standpoint. He's certainly an upgrade on Kerfoot; however the Leafs are already going to have problems retaining Kerfoot beyond this season. Any deal with Toronto has to come at a minimum of 33% retention to match Kerfoot, and if Toronto's going to "dig deep", it should be 50% so as to create a situation where the Leafs can realistically plan on keeping him next year.
With respect to Toronto's prospects. Sandin isn't one anymore. He's an everyday player, that the organization likely overvalues given that he has Kyle Dubas' first draft pick. If the Canucks want a dman in the deal, it'd likely be Timothy Liljegren heading the other way.'
Ultimately, if there is a JT Miller to Toronto deal, I'd suspect it looks something along the lines of:
Miller at 50% for
- Toronto's 1st
- Timothy Liljegren
- ONE of Nick Robertson or Rodion Amirov
- Alex Kerfoot or Nick Ritchie
- Possibly a Travis Dermott <-> Luke Schenn type of swap if it's Nick Ritchie going the other way.
That's a current 1st, a former 1st who's ready to play (Liljegren), a guy likely valued equivalent to a 1st (Robertson/Amirov), and either a contributing middle-aged roster player (Kerfoot), or a cap-dump / project.