Keep instructing, you can build a lot of time if you want it. I had to cancel flights sometimes to avoid going over 8 hours. Milk every 1/10 hour you can, the Hobbs meter is the only instrument that matters in that trainer. Here are some useful tips I picked up for getting the most out of each lesson.
-Actually enforce the suggested "walking-pace" taxi speed
-In flight, say "my airplane" often and for no reason and show them something useless
-Tell them to go around for no reason, even if it is a flawless approach
-If starting out with a fresh private student, teach them to use a slower than normal cruise power setting. they won't know the difference
-Make up a bogus practice area that takes 30 minutes to get to
-After they park and are about to shut down, tell them it would be better to park on the other side of the ramp
-If you suspect the Hobbs meter is going to roll over one more 1/10th (you can tell when it starts twitching) and your student is about to shut down, just begin a sentence and keep talking as if it's relevant to the lesson. Most students won't shut down the engine while you are in the middle of a sentence. You can stop talking once the Hobbs rolls over.
-Oh, and if your school makes you a check airman you can fail lots of people and then they will have to come back to you again for a re-take.