F_V_G
For a queen sized quilt, I go with a base top of 60x84. That is 5 x7 12" blocks or 35 blocks. Fits the top of the bed quite nice. Add a 12 inch border and you have 84x 108.
Might want to trim down the top and bottom borders to 8 inches. That makes the quilt top total 84x100.
Doable, looks great.
tim in san jose