I read all of the horror stories before choosing to buy our Townie. It really made me think it through carefully, needless to say.
I remember having a work truck that had all the guages, like oil pressure, temperature, and a host of warning lights.
It also had a light that would come on when there is a problem and it said "check guages." Having a Townie in the rockies is not for you if you need an indicator lamp to remind you to check your guages, because your guages are indicating that there is an urgent problem.
That said, I have had to replace the head shortly after I got the van, because the timing belt broke. Head gasket set was $250 CAD and the head was $200 CAD - the same as my brother's 1990 Honda civic.
We have driven our van through some tough climbs - one was almost an hour in third gear with the foot almost to the floor. Over the summer we found that we were pushing coolant out the overflow resovoir, (it was around 104 degrees and climbing hard), to which I found that the rad cap seal was shot and the rad was not able to presure up. It was like driving with no rad cap. At that time I also noticed that there were a couple of marred spots on the metal that the rad cap is to seal against, which was contributing to the problem.
I replaced the rad cap and all was good for our everyday driving, but we took it for a hard run last week (we climbed 3300 feet in about 6 miles as fast as we could) and it still pushed some coolant out of the overflow, and when I went to top it up, again there was no pressure in the rad. I will be replacing the tube that the cap screws on to soon, but it is not something urgent for us.
Please note that the temp stayed steady at normal as the coolant was going out the overflow. If the rad was allowed to pressurize, I am sure that everything would be fine.
These vans have a vertical rad cooled with a viscous fan and a horizontal rad cooled with two electric fans. See image:
Though I do believe that the cooling system is adequate, I am not sure that it was designed for life in the Canadian Rockies. I do watch the temp guage over long relentless mountain passes more than I did with our Honda.
From our experience, we tend to keep our head up as we are hitting the mountain passes, but that should change when we replace the rad filler tube. My brother's Townie regularly travelled from Revelstoke to Calgary - and that it another high pass.
I am sure that the other guys will have more input as well. One was driven across Canada...
Hope this helps!