This is a really difficult dilemna. Sounds like your perfect job is only going to come along very rarely so you need to take that opportunity. However, on the other hand, you know that you will be having to continue to juggle all your current home duties. So have a think realistically about what that will be like and whether your DH will help you more than he does now.
I have had the opportunity in the last few years to change from my part time job I have been doing for many years to a full time more stimulating job however I know that I would be putting more pressure on myself as DH won't pick up the slack at all so I have resigned myself to the fact that part time is for me. Also, any time DD is sick, I am so thankful I did not take on full time work.
So having said all that, I would go for the job and try it out. If it doesn't work, you can resign after giving it a good go.