Is this really a problem?
A SAAS client of mine's operational costs are like 1% of our revenue. Ok, they're at Series A/B funding sort of size. they've started to go international and we could also quite easily do an instance per country if we wanted, though I don't know what sort of pain that might cause.
Running ASP.Net/C#/Azure. Azure's a bit of a nightmare, would be running much better/cheaper on a dedicated server in my professional opinion (shock, horror, yes, I said it, cloud is a bit of a con).
I've spent 2-3 weeks per year "scaling" the code, which was written by other people who in some ways didn't know what they were doing and were trying to make it too much like a SPA which resulted in lots of ridiculous, excessive dupe calls for data and over-complicated code. After my last round of optimisation I doubt they'll need to scale up for a couple of years now, the CPU was basically sitting less than 20% and DB was about 40% even in the crazy Xmas rush, and we were on standard tiers (compared to the year I started where they had to turn up to premium a couple of times with 10x less users).