hi scott I have the uno I am 67 13stone, the uno has 10.4ah battery and 3 levels of assisatance low,med,high
the karoo is lighter and has 13ah battery (with option of 15ah) but has 6 levels of assistance (I find on the kudos I would like to be between level 1 &2 to eke out range)
I am assuming a rear rack + panners +locks would be needed adding to the weight.
I think my main concern would be depending on whatever bike you choose where is it going to be locked up, would you want to remove battery each day and lug around aprox 7lbs.
as a slight aside last week myself on uno, shopping uphill level 3, neighbour on Carrera hellcat mtb 29er aged 10 on pavement arrived together, exept he was bright red from the effort.
for a round trip of 6 miles you could get a nice bike for £250-£300 unpowered as others have mentioned