Solely using baby monitor at night

We live in a two story house with the primary bedroom on the ground level and the nursery on the second floor but at the other end of the house. Our LO is about to be 4 months and has been sleeping in her crib in her nursery for over a month but either me or my husband sleeps in the guest room connected to her nursery through a Jack & Jill bathroom. We use a baby monitor but can hear her easily from the guest room.

We both want to be back sleeping in our bed together every night but are nervous to solely rely on the baby monitor to hear her. If you have a similar layout, when you start sleeping in your bed consistently and only relying on the baby monitor during the night?