Hi BillyBobMac,
I really feel for you. Half a dozen years ago (I was in my early 30's) I lost my job in Paris and after several months, I still had nothing, so I moved to the UK where I quickly found an 'entry-level' job (like you, I don't have a degree). I was studying p/t with the OU, and hoping to graduate by 2012, and then land a good job and get on the property ladder: the future was smiling at me!
Then, in 2008, along came the financial crisis. I've managed to remain employed by moving 'entry-level' jobs and putting up with being bullied. My salary is lower than what I made in Paris back in 2001, university fees have increased, food prices have increased, electricity bills have increased, my rent + council tax is 60% of my salary. I had to shelve my OU studies for 2 years while struggling to remain employed so I definitely won't have a degree by 2012.
So, like you, I'm looking to move countries once again, though not back to France, as the jobmarket has become worse since I left, and in France not having a degree is a huge handicap. I'm not that young either and can't do the warehouse and cleaning jobs I used to do in the past: my back just won't take it.
I gasp at the thought of packing my clothes, books, CDs, and DVDs again, and selling or donating my furniture and crockery again. You're very brave to be considering this option with 2 children on your hands.
If that can comfort you, in France, I've known, not just 40-something, but also 50-something who uprooted themselves and moved to a different country, because that's where the jobs were. One 50-something lady I met at my branch in 2008 was relocating to Dubai. She probably lost her job there around 2009 though: my 2 next-door neighbours in Paris, a French-American couple, also relocated to Dubai in 2008 (after graduating from a private business school in 2007 and looking for work in vain for a whole year); in 2009, they were back. Luckily for them, their parents were well off and could pay their removal costs, and their previous landlord hadn't managed to sell the flat, because of the recession, and agreed to give them another lease.
So you have to be careful when choosing your country of destination, especially with children in tow and a shrinking eggs nest. Another option is for one of you (usually the husband) to move abroad for work, and live stintingly in a bedsit, sending back as much money as he can to the other parent at home in Ireland. This could enable you to keep the house and continue pay off the mortgage, but it's hard on both of you: I've known several French people who did this, including some of my relatives, and basically, the fathers would travel back to France nearly every weekend if they were working in Germany, and only once a year if they were working in Africa or Asia.
If you do choose to relocate abroad, you could try and look for a 'bilingual' or 'international' school for your children. It would help them feel less isolated, as they would be with other expats' children (less risk of bullying as well), and they would maintain their level of English while learning another language. These schools are usually fee-charging, but some of them do have 'scholarships', or will agree to negotiate affordable fees with you.
One thing to be wary of is the exchange rates. When I moved to the UK, £1 would buy me about 1.45 euros. Now it's worth 1.11 euros, and it's made life very difficult for me: saving for retirement in France, or paying for French private health insurance is just impossible. I can imagine that an Irishman who had got a mortgage in Ireland back in 2007, and was paying it off their salary in sterlings in the UK, could be in difficulty now. Nearly happened to me as well: back in 2007, I was considering buying a rental property in France... So now I'm looking for a country which uses euros, although if Marine Le Pen gets elected in 2012, she wants to go back to the Franc...
I hope everything goes well for you, and once again, thumbs up for your courage!