Agree with drover about background stuff that chews power.
Our setup for what it's worth....Have had an inverter in previous van but rarely used it.
Laptop has a 12v charger but it doesn't charge just maintains charge. We now leave laptop at home as iPad etc does what the laptop was used for. No longer run a business so simple Internet, banking and email are all that's needed. Have yet to discover that Facebook etc are necessary when trying to escape the daily grind...my daily grump.
We also have multiple 12v sockets in van and in vehicle so all toys are charged directly from there.
The usb cables for the 12v are also used with several 240 plugs with usb sockets when on 240 so don't need separate chargers.
TV can run on 12 or 240 with accessible sockets but still haven't used the 240 plug as we are lazy and seem to always run it on 12v as battery always seems to be close to full. We do monitor it carefully and, if in doubt, we just decrease our usage till it gets more solar. We also have a few portable power packs which will keep charge up in iPads etc at night when we seem to need them more and just charge them up in the mornings.
Extra power margin we get from a portable deep cycle battery which we don't always take...only to places where we want to veg out and be couch potatoes for a week or so.
For a laptop I guess an inverter is better but if you check to see how much time you get from the one charge and use a 12v charger to maintain the charge it might work. I'm not convinced that an inverter is cost effective with laptops....240 is definately better and faster.....just depends on time between charges and anticipated usage.
We also charge camera batteries, rechargeable torches, toothbrushes, ereaders etc as well as phones which always seem to need a charge.
There is a spreadsheet which allows you to calculate anticipated input / output based on draw from each piece of equipment. I'll try to locate it and post it as I found it very helpful.