London to Portsmouth - is this doable?

[mongrel79]

Hi Forum
I want to cycle to Portsmouth and back from North London. Is this doable? I have many questions...
I've been struggling to find a route - National Cycle Network route map doesn't have anything useful in it: http://www.sustrans.org.uk/webfiles/general/Sustrans_National_Map_2007.pdf
So I was wondering really is this possible?
How long do you reckon it'd take? It's about 100km...
I cycle about 150km a week but have never done more than 50km in one go - will it be hard going?
Does anyone do a lot of intercity cycling in the UK? Is it difficult to find a route that isn't a massive A Road or motorway?
Thanks in advance - it'd be great to find out that intercity cycling is genuinely feasible!

 

[Revolutionary]

A bit more than 100km I would of thought.

I sometimes use: http://www.theaa.com/travelwatch/planner_main.jsp

Make sure to select 'avoid motorways'.

Anyway, of course it's doable but avoiding motorways is always a problem...