I suppose the best way to look at it is this.
You can't use a charger, so you either have to disconnect or let it drop. Or get a janky solar charger that may or may not keep it topped up.
If transport mode has not been deleted it is almost certain that the drop will trigger it. If disconnecting triggers it then that's possible too.
But transport mode should have been deleted; if it has disconnecting it will cause no issue and you'll be able to start straight up on your return, you can't do that with a flat battery.
If you have a proper smart charger you could also bring the battery inside and leave it on to keep it as healthy as possible.