Newbie needing help-

I'm just starting a counted cross stitch design from Boyd Designs for Janlynn called "Summer Farm." It’s very pretty- it looks like a watercolor painting. Finished size is 8"x12" if done every 2 on 27 count even weave fabric. If I don't mind it being smaller, but want it to be more evenly detailed (higher resolution), so can I just use every 1? If I did that it would be about 4X6? would I have to switch from cross stitch to just a half stitch (petite point stitch) to get it to not be bulky and lay right? I'm used to just following the directions, and this is a gorgeous kit, with about 30 different colors of floss. I'm also cheap and don't want to have to buy new floss and a new canvas if I mess this up. So thought I'd ask help from those who might have adapted patterns before.