Unfortunately, it's not possible to change default context (which is 'Everything'). The best workarounds are: -to use Saved Search (as you've already mentioned) -to add this Saved Search as context.
Both variants require one extra click for showing sample you wish, but I beleive it's not so annoying. Moreover, context allows you to execute other searches in respect of choosen context.
To add your saved search as context, navigate to Saved Searches section in side bar-> your saved search-> click Pin in a drop-down menu. Search will appear in Context Searches menu, top right corner of the page.