Using my CSS Modules plugin you can import SCSS files as shown in my React Toolbox example app. Starting from an empty project, it would take about 6 lines of configuration in package.json to do so:
"cssModules": {
"extensions": [ "scss" ],
"explicitIncludes": [
"node_modules/some-npm-package"
]
}
Granted, you can’t import CSS files from NPM packages right now, so that could be a dealbreaker (but I should be able to change that).
If you want to stick with standard Meteor, it’s an easy way to go.