1. 'clutch springs are the weak link'
They are kinda puny, but they don't have anything to do with this issue.
Take any bike (or anything else with a wet clutch) and check the difference between pushing the cold beastie with the trans in gear and clutch engaged (lever/pedal pulled/pushed) to pushing it in neutral.
You'll be lucky to push it anywhere with the trans in gear.
Personally, I'll be skidding my rear tire if I try pushing my cold bike in gear with the clutch engaged. Not a whole lot better when it's warmed up, either.
re: 'thinner oil help?'
Yes. 10-40W (given that you're running motor oil) isn't a very good choice for cool weather.
re: '..put in an extra spacer'
Maybe. But, follow the method to determine if that's the issue. Basically, if the lever º is more than 90º, remove a shim (washer). If it's less than 90º, put in a shim.
Example...after I installed vesrah plates from frp, my clutch stack was a bit 'thick'. I removed a shim.
The reasoning being fairly obvious. The closer you are to having the midway point of the pull arc @ 90º, the greater linear movement (cable pull) you will have.
Capiche?
Agreed. Basket fingers aren't indicated unless once you are running it is difficult to shift into neutral.