I ended up doing the commute on Friday (nice weather here in New England then- now it's 40 and pouring As predicted it was rather exhausting but worked out ok. My legs don't get tired but my hands and feet fell asleep as they always do when I'm out of shape.

I did a steady 23-26km/hr and the distance ended up being 48km going up Rt62 to 225 through carlisle and westford then 119 into Pepperell. I was more than happy with that as I rode my commuting bike with fenders, panniers and the lot. Luckily the bridges were all open so I didn't have to wade through any rivers. I'll give it another shot when the weather improves.

I think one day a week- maybe two until I get conditioned will be OK. I'll try to update the thread with news on how it goes. Figure that would be useful for others who might be searching on the topic.

If any locals have ideas for a better route I'm all ears- here's how I went: