So sorry for your loss, its such a tough thing to go through so my heart goes out to you. Its very hard to tell you what to do as what is right for one may be wrong for another, but I will share my experience with you.
I had a mmc last year at 11 weeks - baby had stopped growing at under 6 weeks, but took 5 weeks for my body to realise & start to miscarry naturally. I had 4 days of brown blood on wiping & mild cramps, followed by 3 days of severe cramping & heavy bleeding after which I could take it no longer & went to a&e for some stronger pain relief. I miscarried in hospital, Stayed in overnight & had d&c the next day to remove a bit that hadnt come away, as just wanted it all to be over.
The surgery itself was actually fine, apart from feeling a little groggy for the first day there were no ill effects & only light bleeding for a week or so. With hindsight if I'd been given a choice I'd definitely choose a d&c - much less traumatic, no pain, no waiting around for things to happen for an unknown amount of time etc.
Have you got lots of irl support esp for helping out with the kids? I found that to be a big help, & its one less thing to worry about. As for work - I told mine & they were very understanding said to take as much time as I needed. I felt able to return after a week off mostly as I wanted to get back to normal (myway of coping).
Whatever you decide, hope it goes ok.xx