Well I don't bl**dy instruct to earn a living!
Spent 7 months last 'summer' full time instructing and ended up owing lots of money (mortgage, kids, cars, blah blah blah). And I was living in a bl**dy caravan! Have spent 14 months (and some to go) paying for instructing for 7 months last summer. I saw my full-time job as merely subsidising the (rather lavish) life style of the flying club owner. I am now in the enviable position of instructing part-time, so I fly for free, and the 'income' generated pays for my medical, ratings etc, and the odd hour in the twin. Don't think I feel hard done by - I know I needed the experience to get the part-time job.
My advice is to instruct during the summer full-time and part-time or not at all in the winter - you will not lose a great deal in terms of airline jobs at the moment cos there ain't any.