I'm almost scared to ask...

Don't  be  afraid  Kdee  there  is  any  amount  of  info  on  this  very  subject  !! 

Look  at  the  "Tips  for  making  caravaning  and  touring  cheaper"  or  some  such  title  on  here  --  the  first  posting  on  it  is "How  to  survive  a  non -  240  volts  EHU  site"  and  it  was  posted  by  MERVE  --  a  gentleman  from  this  club,  well  learned  in  this  very  subject  !!

If you fit a solar panel and controller ,plus an inverter wired to the lesure battery you can run mains powered items from that ,and all that lovely power is free from the sun

If running from your leisure battery, only your 12v sockets and lights will work. Back in the 'good old days' we all ran off gas and a leisure battery was a luxury so it can certainly be done.

And car battery if carefull

Strange isn't it how often this question crops up, nothing wrong with that of course some folk just don't have the back ground to know it can be done.

Our first caravan didn't have a 12v battery or mains, no lights other than a gas mantle and the water was of course cold and worked from a foot pump. Oh the good old days (not). 

To the OP yes it can be done, even without a solar panel you can stay off grid for a night or two, however you won't be able to use microwave, hairdryer etc. If you do go down the road of a Solar panel and want to use mains electric items then you would need to get an inverter fitted. We have a portable solar panel but don't use an inverter as most things we would use are 12v or gas.

I will strongly second checking out the thread, How to survive without EHU.  Long but very informative.

Below is  the fresh thread Merve started after the web upgrade.  You'll need to copy and paste into the address bar.

https://www.caravanclub.co.uk/club-together/discussions/welcome-hobby-talk/tips-for-making-caravanning-touring-cheaper/how-to-survive-a-non-240v-ehu-site/

Or click here 

 https://www.caravanclub.co.uk/club-together/discussions/welcome-hobby-talk/tips-for-making-caravanning-touring-cheaper/how-to-survive-a-non-240v-ehu-site/ 

There is advice in the motorhome media on living without EHU. How you go about it depends on where and when you motorhome. For example, solar panels will be less useful in the environment you describe. 

I went for two 110 batteries and these keep me going for at least 4 nights off EHU. Never tried for longer but I'd guess I could go to 5 without a problem.

Bear in mind that adding solar panels, generators and extra batteries increase your van's weight/axle loading. Also your charger may struggle with two big batteries.

We've been towed off site too often and now only pitch up on hard standing or where there is no doubt the ground is hard.

We have an 80W Solar panel, two 110amp Leisure batteries and will probably not need hook-up during the four weeks we are in France starting on Thursday.

Unless you sit watching TV for hours on end, which takes a lot of power, you can manage for many days, or even weeks, with a decent size Solar panel and an extra leisure battery.

Get the largest Solar panel you can afford, make sure there's enough roof space to fit it, and good quality Leisure batteries and if you have on-board toilet facilities the World is your oyster.

In the UK you'll find if you stop on Campsites hook-up is usually included in the price but doing Continental touring, with an element of wild camping included, then solar power and an extra battery are the best way forward.

I'll agree about Poolsbrook C&MC site – we stayed there for around 10 weeks last year and it is a good'un.

It isn't only the electrics you need to consider if using off grid type sites. No idea how big your MH is, but caution is required on some sites in terms of underwheel conditions. We always walk the site and consult with owners when touring early and late in season, especially after rain. We invested in a pair of Bridging waffle plates (to be found on 4x4 websites) and park our drive wheels on these if things are a tad soft. Not overly expensive, and we carry ours slid behind roof ladder and bike rack at rear.

Getting stuck isn't confined to MH's either! Last year we used our Jeep to rescue a pair of less than bright caravan users who had unhitched and rather foolishly tried to use motor mover to turn and slowly put van into another place. They had pivoted van wheel deeply into soft grass, cutting it up badly! Neither had a tow vehicle properly suited to conditions on grass and would have done untold damage to a lawn like CL.