Conditional cards

[tamorgen]

Good evening,
I'm trying to figure out how to set up a set of cards, based upon Christmas season. I've got a binary sensor set up that I can pull the state from, and for a single card it works great.

  - type: horizontal-stack
    cards:
      - type: conditional
        conditions:
          - entity: binary_sensor.christmas_season
            state: 'on'
        card:
          type: custom:mushroom-light-card
          entity: light.family_room_outlet
          name: Christmas Lights
          use_light_color: true
          tap_action:
            action: navigate
            navigation_path: /lovelace-mushroom/christmast-lights
          icon: phu:christmas-wreath
          fill_container: false
          show_color_control: false

What I'm struggling with is how to apply it to a group of cards/horizontal-stacks.

I have 18 cards, including the Christmas Lights card. On each horizontal stack, there are two entries, so when the Chirstmas Lights card is active, it's on it's own line, and the last card is on it's own line.

I'd prefer that the Christmas Lights card shares a horizontal stack with the next card, when it's active, but when it's not, that next card shares the line with another card. Essentially the conditional card shifts all the remaining cards.

What it looks like now:

What it looks like without Christmas Lights card:

What I want it to look like with Christmas Lights card:

I have the YAML file for all three screenshots above. I've attempted to place the conditional type at the top of the Rooms section, but I get all sorts of YAML errors. I've also attempted {% if is_state('binary_sensor.christmas_season, 'on') %} and else if after the first set of cards, and then of course an endif after the second, but all it did was combine both menus.

Any suggestions?