How do you know when/if to get a second cat?

[Furrybaby]

We adopted 2 cats (brothers) in April last year. Very sadly one brother had to be put to sleep in September after being hit by a car. This was a surprise as we don't live near a busy road and I was devastated. Absolutely beside myself. We only had him a short time but I love them both dearly.
They were mostly independent of each other but would sleep together during the day some days and play when they were in.
It took our cat a little while to accept his brother had gone and would look for him when the weather was bad (he didn't like being out in the rain). Once he had come to terms with this he seemed to "grow" into being the cat of the house. He'd sleep in places his brother used to sleep in and seems more confident (I think his brother was the dominant brother).
However, we'd thought of getting another cat to keep him company but reconsidered as it seemed he liked being the only cat.
However. I think he may be lonely. He has found a cat up the road that he will go and spend time with, he will wake us up in the morning so we can sit with him.
What do you think?

Cats are good at bonding if they are introduced properly. We now have 5 and the older pair of brothers have ‘adopted’ the boy kitten and sit and groom him! You could have a look at local rescues for a cat that is a similar age to your boy.

We've always had multiple cats and have found it's easiest to introduce a kitten rather than another adult.

We currently have three males (all unrelated) and they make a fantastic little trio. They're 8, 3 and 8 months at the moment and the 3yo's confidence has improved endlessly since we got the kitten.

They play constantly and always curl up and sleep together. The 8yo can't really be bothered with their nonsense much but he will play with them and they all sleep/groom each other and share resources quite happily.

It took the older boys less than 48 to accept the kitten.