He's having a decent season, his stock will be higher by then if that form continues. He has more than one team already interested in him, why would you presume that interest would wane in the summer?
If we survive this season then we should consider selling. But if we drop then we have a seasoned Championship striker, with a solid season at that level under his belt, ready for a hard season. It'll be like a new signing.
We hold all the cards when it comes to Cannon, no need to pull the trigger now. Consider lighting a longer fuse and resist a knee jerk sale.