found a nice compromise that'll keep me going for a while:

I normally walk the dog, then get in the car to go pick up the baby (takes about 45 minutes to do both)
Yesterday I cycled to the nursery with the dog in the front basket (small dog, 7kilos), and then put the baby in a harness thing (strapped to my back) and WALKED back with the dog sniffing things and me pushing the bike. time: 50 minutes ie only 5 minutes of my day lost (no loss). Bit of a pain pushing the bike, but a good compromise for the next few months until baby is big enough for a bike seat.

good point about the speed of cautious cycling, thanks