Turfing it is probably the best solution, though if you can't manage your vegetable garden now, will you be able to in the future? If not, you could just use it as another planting area, using low maintenance planting.

I am sure that we will all reach this position at some point and I am sorry that you feel unable to continue with what was probably a fond pastime. Perhaps you could find a local gardening club, or perhaps the local council has a list of people waiting for allotments, who could pass a reliable person on to you. If you could find someone who wanted to grow veg. but had no space, you could probably both benefit by sharing the produce. Do make sure that it is someone reliable, perhaps a neighbour could recommend someone, or a trip to the local allotments (if you have any) could produce someone - gardeners are usually friendly people and helpful!

I was just going to write the same as Honeysuckle. If you can put up with someone coming into your garden it would be a win-win situation.