Keurig users...help!

I could not find a strong enough blend for the largest cup offered, and even the largest refillable K-cup didnt hold the 1/4 cup needed for a "4 cup" (coffee cup is 6 oz) 20 oz Yeti. Plus the Kups were .50~.75 a piece. Might as well drink 210F $1.00 McCafe singles.