dls;I did an all nighter thats how I usually do my briskets too.put mine in @10.30 pm.no pre heating the cs,& brisket was @ room temp of 72 degrees.I use a maverick-et-73.I followed the recipe as close as I could,cs was on 225.let her go until 8:30am the next morn.internal temp was 180,so I pulled out of the cs,I foiled & I poured the sauce over it & put back in the cs but I left the temp @ 225 instead of bumping it down to 150 as the recipe calls for.I did this on count of the internal temp already was up to 180 & I did'nt want to undercook.I cooked for another 2 hrs,until internal temp was 195,pulled the brisket out of the cs & let rest for about 30'mins.total cooking time was 12 hrs.but I went by internal temp as we all do,you know the saying,it's not done till it's done.I do over nighters quite a bit.I think you will be alright @ 200 & bump up to 225 in the morn.as you said.do you use a maverick or other brand of thermometer that you can set your meat temp & you can put it by your bed so that it will alarm you if it goes past your set temp?this is what I use & love it so far.hope this helps.
Richard