By release of infrastructure money I hope you mean that Feds are finally on board because I do not see the possibility of Ontario releasing their billion $s without federal commitment being there also. Otherwaise Ontario would have done it already.

I do not consider the money availability as profound as the actual announcement that the road is on the go.

Soooo, money wise I think more like 3-5 $s while for the road much as you suggest a spike to 7 but may be conservative.
However I do expect in both situation a retrace back within days to weeks to about half of the peak.