Camping with a CPAP machine

Hello all, I've done a lot of trawling on the net but can't find the answer I need.

We have a poptop van fitted with a 105 Ah deep cycle battery. My wife uses a CPAP machine (Heatlhdyne Tranquility Quest) the only thing I can find out about the power consumption is that it's rated at 75VA. I have tested it and it runs perfectly on a 300 Watt inverter but I'm wondering if it will run all night?. We have a battery isolator to recharge the battery while driving but I don't want to run out of power for lights etc.

Any info, expriences or advice will be appreciated.

Thanks Jeff