PCB layout for CAN bus transceiver
I've added a 120 R res on the CanH and CanL with a jumper header in
case it needs to be terminated

Do you realize that this jumper will probably affect the signal more than 30mm traces? I am saying 30mm because you'd need about 10mm for transceiver in between your two points.
Anyway, at this distance you should be fine no matter what you do. Having said that,

I would recommend placing transceiver next to connector;
If you do (1) then matching traces becomes pointless;
At 1Mbit you have relative freedom of routing TX and RX. Of course VIAs should be avoided, but that is true for any design, not your case in particular.