There are a lot of variables to consider in making this decision. For example, I have found that there is almost a drag on the house batteries when left connected in storage. That makes the case for either disconnecting them by a switch or just unhooking them. In either instance, make sure that the terminals and surrounding areas are clean, as that is a source for battery drain.
I see no reason to remove the batteries, but it is essential that they be fully charged while being stored. I leave mind installed and connected, but I also have the motor home connected to shore power when in storage. This means that I continue to service them year around.
I recommend that you disconnect the house batteries while in storage after fully charging them. If fully charged, they should not freeze, but if you have a bad cell, all bets are off. There are a number of previous posts on this issue, and there is no shortage of individual practices, and most are valid given the circumstances. My recommendation is based on the assumption that you do not have access to power to charge them other than the generator.
2007 Dutch Star 4320
2010 Mazda Miata 6 speed