thepedster said:usually I find a minute or two at idle from cold gives the oil a bit of extra viscosity
Warming the oil reduces viscosity, it doesn't increase it.
If you go ahead with this be prepared for it to get very messy. IME, it's very difficult to catch threads on sump plugs when you are under pressure to do it as quickly as possible and oil is peeing out everywhere

You could simply drain the oil into a nice clean container and then pour it back in if you are dead against changing it.