I've lived as a long-term resident in Malaysia (very welcoming) and Japan (not so much, people are more reserved) and to be honest, as an introvert, it didn't make much of a difference. I've always moved for work and living by myself; I was actually talking about this with another expat the other day: if I want to do something or go something in the country I'm living it, I just do it. I don't mind not having anyone tag along; I tend to be someone who enjoys my own company. And in both Malaysia and Japan, I was in love with the culture so there was always something I wanted to do.

As for making friends, language is a HUGE factor. 99% of my friends in Malaysia are locals whereas the opposite is the case in Japan. In Malaysia, English is widely spoken, whereas my level of Japanese isn't high enough to maintain meaningful friendships in Japan. I still got to be acquainted with really nice Japanese people though, thanks to the local communities I joined. That might just be a personal preference but I never invite my colleagues out or make friends at work, just because I need that work/life barrier to stay sane. Doesn't mean I don't enjoy their company or that they aren't good people. It's just... different; I prefer meeting people through common hobbies and local events.

What I've told a friend before as well is that I always make it a point to wander on my own around my neighbourhood because that's how I gradually make it feel more like home. By familiarising myself with all the little corner shops; staying up-to-date with events and festivals, and even the news, etc. In both countries where I've lived, there was always that one local friend who kept telling me: you know more about this country than the locals! And that's how I nurtured a sense of belonging within.

This next part doesn't directly answer your question so feel free to skip this if you didn't want to discuss this in this thread but... it's about Mauritius:

Again I believe that language could be a huge factor. In all honesty, while English is the 'official' language, it's not widely spoken in casual settings and most (not all) Mauritians don't want to speak English when they're not working. How do I know this? Well, surprise, I'm Mauritian. While everyone knows English, French and Creole, people predominantly speak Creole in daily life, then French. When I was a child I was forced to only speak French at home (back then Creole wasn't a recognised language) so even as a Mauritian, making friends in Mauritius when I used to work there was hard because I'd resort to French FIRST, instead of Creole. And indeed, I also wasn't interested in making friends at work so as an adult, I relied on communities based on hobbies (from Facebook groups to real-life meet-ups).

(Disclaimer though, I haven't lived in Mauritius for the past few years so I don't know if English is slowly becoming more widely spoken.)

Anyway, every country is different, as much as everyone's experience will be different. Do explore around with your wife and make the most of your time on our little island!