I don't know your specific components, but, as a general matter, a lot of people can do with far less power than they think they need. But, there is no reason to go lower and lower just for the sake of seeing how low you can go. With solid state, you can achieve fairly high power levels without that much additional cost, so there is less of a reason to go very low in power unless you are taking a fundamentally different approach to design (e.g., First Watt, an offshoot of Pass Labs).
It is a different story if you are looking at tube amps. With tube amps, there is quite a bit more variability in sound quality and achieving higher power often comes at a sonic price. That is why low power makes more sense, if you can live with the lower maximum volume level. Most of my favorite tube amps are under 8 watts, although there are some that I like that hit the heady rating of 100 watts per channel.