Lead Acid Battery Winter Storage

[Selkirk]

My trailer is equipped with the factory-supplied Victron solar controller, two roof-mounted solar panels, and two 6V lead acid batteries.

It will spend the winter at an uncovered storage site.....from early Oct - late April/early May. Snow and sub-freezing temps are expected. However, the area is prone to reasonably frequent warm spells (chinooks) through-out the winter season, so I don't expect the trailer will be snow-covered 100% of the time.

I understand that LA batteries don't carry the same risk of cold weather damage in low temperatures as Lithium, provided that the acid levels are properly maintained and the battery is initially stored with a full charge.

I suspect the optimal procedure would be to disable the solar controller (which I think can be done via the Victron app), fully remove the batteries, and store them at home connected to a battery maintainer.

However, how risky would it be to just keep the batteries in place over winter with the trailer's main disconnect switch open (which still leaves the solar controller connected)...and rely on the solar panels to occasionally charge the batteries whenever they are not covered by snow? The storage facility is close enough to work that it would not be that big of an issue to occasionally stop by and clear off panels....if need be.

Thoughts?