Mate, you're a language school's feckin wet dream!
'm here 5 years and in that time I've met one man in his 70s that spoke English, just doesn't happen,
I know a few (and even older) in Warsaw, but all ex-diplomatic service, ex-WSI or retired English teachers.
Work-wise I think you'll do fine, but Jesus don't work for free. The other native-English speakers at your school won't be too impressed with you because you'll be either taking their work or you'll be forcing their price down and that's not cool, Christ knows, langauge schools treat their staff like crap anyway and the pay isn't great.
That's really important - it can be quite competitive in the nicer locations. You'll also probably get a lot of requests (perhaps more than you'd want) for private lessons (experience and ability are highly respected in PL) so really you need only do a couple of lessons at a language school - most of them now don't recruit for full time posts anyway. You'll find IELTS rather rare here (just not marketed as much as, say, Asia) but plenty of FCE preparation.
It might be worth just turning up here first and seeing if the rest falls into place. If it doesn't, it's not too far to go back, if it does, all the better...
Just an idea for the short term, why not try this: angloville.com.
A friend who's a semi-retired language teacher does this. Most of the participants are apparently slightly older than the ones in the picture by the way - a lot of company people. I've heard it's good to do, all 1-1 teaching and you could make some very useful contacts in PL which could lead to something excellent. They don't pay but do put you up in a nice hotel (a great business model for them and one reason I haven't done it myself).
I've sent you a PM