I would just get on with it. I reckon at least half a dozen will turn up.
The stories on here remind me of a colleague I used to have who invited 40 people to her 40th birthday party. (30 adults and 10 kids aged 7 to 14-ish.) The start time was 7pm...
7 people turned up. (Me, and my husband and 2 kids, an ex colleague of hers, and 1 neighbour and her husband.)
It was heartbreaking to see. It was her 40th, and she had put on a huge spread, and got lots of booze for everyone, and she and her daughter and son had done some music mix-tapes, and put streamers and balloons up, and 7 people came. We were the first there at 7.10pm, and she was beaming from ear to ear; very excited!
8pm came, and no more people were there.
She was looking really angsty, wondering where everyone was. Then, just after 8pm, her ex colleague, and 2 neighbours came (just a few minutes apart...) 8.30pm came, then 9pm... No-one else.... 
She kept saying to her husband 'where IS everyone?'
It was so awkward and uncomfortable. By 10.15pm, it was clear that no-one else was coming...... The atmosphere was quite low and dull as she kept going off to the bathroom (we found out later it was to cry,) and so regrettably, me and the others decided to leave at 10.30pm-ish.
Didn't see her again much after that; she sort of drifted away....... humiliated I think, and didn't want to see people.
Never forgot this. It was very upsetting.
I genuinely hope at LEAST a dozen turn up OP.