Look to revamping the indoor plants. They have survived months of being indoors and its time to repot, replenish and fertilise. Salts build up in the soil from fertiliser and lack of drainage due to having saucers underneath them continually. If pots are small fill up a bucket or crate with Seasol (30mL concentration per 9 litres of water) and then soak the pot for a period. Wait for all the bubbles to come to the surface and then let drain. This complete soaking will ensure all the potting mix is wet and the salts are reduced in concentration.
Consider accumulating more indoor plants than you have space for inside. This allows them to be changed regularly to a protected position outside as nothing is better than natural light for growth. This can be done by taking cuttings from some easy to grow varieties and propagating in water. Some of these species can be grown in jars of water indefinitely and are perfect choice for beginner gardeners.