There is no bus TTC to Crossroads to my knowledge, though you might be able to blag your way onto a bus to the nearest 'downtown' hotel and walk from there.
Crossroads is however, just about walking distance from the Marketplace bus stop. There is a sidewalk all the way along past the hotels. There are trees all the way for shade, but you will have to run into one of the hotels if it rains.
I would guess a 20 minute walk.
Goodings has a dedicated phone line in their entrance to call a cab if you don't want to walk back with your shopping.
Andrew