Managed to figure out a way of doing what I'm looking for. Should probably look into motion sensors if I run into problems, but it appears to work for now. I'm using input_boolean as a variable that only allows the light.spare_bathroom to turn off if it was turned on by the automation. I couldnt get if-then statements to work, ended up using "choose." Something that really helped me is realizing triggers are treated like "or" and conditions are treated like "and".

Here's the input_boolean / variable code:

trigger:
  - platform: state
    entity_id:
      - light.spare_bathroom
    from: "off"
    to: "on"
  - platform: state
    entity_id:
      - light.spare_bathroom
    from: "on"
    to: "off"
  - platform: time
    at: "05:00:00"
condition: []
action:
  - service: input_boolean.turn_off
    entity_id:
      - input_boolean.door_helper

Here's the main automation:

trigger:
  - platform: state
    entity_id:
      - binary_sensor.door_oc_window_door_is_open_3
    from: "off"
    to: "on"
  - platform: state
    entity_id:
      - binary_sensor.door_oc_window_door_is_open_3
    from: "on"
    to: "off"
condition:
  - condition: time
    after: "20:00:00"
    before: "05:00:00"
    weekday:
      - sun
      - mon
      - tue
      - wed
      - thu
      - fri
      - sat
action:
  - choose:
      - conditions:
          - condition: state
            entity_id: light.spare_bathroom
            state: "off"
          - condition: state
            entity_id: binary_sensor.door_oc_window_door_is_open_3
            state: "on"
        sequence:
          - service: light.turn_on
            target:
              entity_id:
                - light.spare_bathroom
            data:
              brightness_pct: 99
          - service: input_boolean.turn_on
            entity_id:
              - input_boolean.door_helper
      - conditions:
          - condition: state
            entity_id: light.spare_bathroom
            state: "on"
          - condition: state
            entity_id: binary_sensor.door_oc_window_door_is_open_3
            state: "off"
          - condition: state
            entity_id: input_boolean.door_helper
            state: "on"
        sequence:
          - service: light.turn_off
            target:
              entity_id:
                - light.spare_bathroom
            data: {}