I assume you decided to rehome an older "pup" rather than take on an 8 week old. Very wise! I had forgotten what hard work a new pup is when we had our last one. He is now 4 years old, reasonably civilised, although acts like a 4 month-old at times!! Typical Labradoodle brain I am told, but so loving with it. As I sit here trying to type this, he keeps bringing me his "eye", the last tiny bit of a stuffed duck toy he's had all his life, to throw for him. Its soggy and filthy, but it is his favourite thing.
Your new boy is a very lucky dog to have a motorised owner - as you say, must not overdo the running yet!!
Yes, it is getting chilly for cycling ( need good windproof clothing ) and far too many wet days. Roll on Spring, for happier dog walking and cycling ! !