Count on an hour more than an extract batch. When I do mini-mashes, I'll use a really big mesh bag (it's as big as my kettle) and a little over a quart of water per pound of grain. After an hour, I add all the rest of the water for the batch at 170F, or so. Then gently stir the grain for 15 minutes before removing the bag and adding the extract. I've gotten great results.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk