Thirsk to Pickering

Blimey,  it only took 10 minutes for that post to appear and that was after 8 mins waiting then Service Error appeared !!  I tried the 'Profile' page and there it was all pretty and dust free  

No, I would say not. But it is much longer, much busier (and with HGV’s,) and probably gets more snow and ice than Porlock. The ban on towing is possibly outdated nowadays, but you would need a tow car capable of steep hill starts, it’s LR territory really. Better that the ban stays. It is frequently shut when vehicles don’t make it.
We were heading up one Winter and got diverted, lorry had shed a load of steel bars that had torn up the tarmac and caused havoc on the bend. Took a while to sort out. It’s fun in the snow as well🙏

Certainly prone to more snow and ice is Sutton Bank, not that I have used it since retirement, but not in the same league as Porlock in my opinion to test your motor. 

We stayed on a site not too far from Porlock about 10 years back, having got there avoiding the steep hill.  Out for the day solo, we were going back to the site via the hill, and came upon a small caravan rolling slowly backwards down the hill, still attached to the equally small tow car!

Update re Thirsk- there are road closures due to gas pipe works in Thirsk.This can mean you being sent on a hold up inducing  detour.CMC site is best approached from Station Road direction via Carlton Miniott,to avoid snarl ups.

That's the Stelvio - bit more difficult than Sutton Bank

Like a lot of things, how challenging you find Sutton Bank will depend, to a large extent, on your expectations.

I did it once only, some years ago in my previous motorhome. I had been told it was no trouble at all in a motorhome - just like many are saying here. So I expected it to be no problem, but I found it difficult and very stressful. Oh I made it, but it was a close run thing, and I was a bit of a sweat ball by the time I reached the top. 

If you went into it expecting problems, you'll probably sail up and wonder what all the fuss was about!

All a matter of perspective, but I can say honestly that I would not do it again. 

Just an aside, there is an easier toll road at Porlock Hill so you have a choice if you need to take the coastal route.

The Hartside Pass in Cumbria, that's a similar vertical challenge. But I think Hardknott Pass comes out tops....