You can only precondition with a level 2 charger. With a level 1, you would have to wait until charging has stopped and then precondition off the HV battery which will significantly reduce your EV range.
Also, I think you said you will have to do this with and extension cord. If so, a 40 amp extension cord is a specialty item and will be very expensive if you try to do this with a level 2 charger. If there is part of your house close enough to the car, it may be better to add a level 2 receptacle and skip the extension cord.
Here’s one way I thought of to lock the extension cord and charger. (Thanks to Sriyad and AlanSqB whose ideas I use here)
1 Lock the Honda charge handle to Car with small padlock through hole in release lever.
2 Lock extension cord to charger cord with padlock large enough to go around both extension cord and charger cord by making a loop close to where they plug in to each other. Pick lock that’s not to large to slip over plug/receptacle ends and not so small it pinched the cables.
I’m not sure about being able to lock at the house outlet. All the lockable covers in my big box hardware stores have plastic covers with holes for a padlock. I could just yank on whatever’s plugged into it and off it goes. Remember to get a cover rated for wet locations and a cover for where charger and extension cord plug together (that last one is cheap).
Good luck and let us know how you get it to work.