Go for it! The thing is ..... You will be coming back ...and IMO it wont permanently damage them or anything unless your kids are sensitive or have separation anxiety. in my experience the grandparents keep them so busy with fun activities they won't even realise you are gone!
I'm probably biased because I have left my husband and kids ( shock horror haha) for 10 days. Mum took me to Singapore after I lost a baby at 14 weeks. It helped me be a better mum having time out, to be honest so I don't feel guilty. I spoke to DD every day and she knew I loved her.
And DH and I left DD for 4 days and honestly she had the best time with GPs and won't remember, or be emotionally damaged or anything from only a short time away from us.
Just my opinion. Oh and also, I'm totally jealous too