Having waited a couple of extra months my bitch has come into season but now the damn snow might be a hindrance.
Progesterone tests results were

Monday (day 9) 7.3
Wednesday (day 11) 20.8 and advised mating today (friday) or tomorrow.

Had 2 x 20 minute matings on day 11 & 12 (Wed/Thursday)

Couldn't get there today & tomorrow looking dicey re: weather & my OH is stranded in Europe so if I venture out & get stranded I have no cover for the other dogs left at home.

I'm crossing my fingers the sperm will hang around long enough from existing matings for the eggs to mature but I would appreciate comments/opinions.

You should be fine.  At 20.8 she should have just ovulated, eggs fertile by around Friday (hence Fri/Sat being best days to mate).  Therefore she's been mated day of ovulation and day after ovulation.  Unless sperm is below average it shouldn't be a problem for it to survive 24/48 hours.  One of my girls was mated day before ovulation and day after ovulation and she had 9 puppies.

sperm can live upto 5days after mate so i wouldnt be worried at all ,iv been told more girls are produced that way?? so im waiting to see as our gitl was mated early too, all the best!.

Thanks both. Managed to get there on Saturday and get another mating so fingers crossed now.