If you're comfortable riding with clip-ons, then stick them on. There are certainly some sections where they'll come in handy.

I used clip-ons on my road bike at short notice last year after finding my TT bike wouldn't fit in the flight case I borrowed.
Worked out well, there are enough long/straight/flat sections to use them, and you also have the benefit of being on the hoods to brake/shift on some of the trickier descents (e.g. down into Wiseman's Bridge). My road bike is also lighter and I climb a lot stronger on it, which helped on the climbs (e.g. up out of Wiseman's Bridge!)

Thanks both, did you change your bike set up to a TT style setup or just had the clipons with road setup? I'd have to swap out my seat post to get me further forward in my case for example. Ie which position do you recommend optimising for

Didn't have a lot of time to really faff with position.. realised a couple of days before my flight that the TT wouldn't fit so it was a case of buying whatever I could find in stock locally (Profile ZBS), then installing them and getting them to a comfortable position once I got to Wales, three days prior to the race. Used the saddle from my TT bike because I knew my rack/bottle cages worked with it and it's what I'd trained with for longer rides. Installed that on the road bike's seatpost, ended up with it jammed all the way forward.

Did one test ride to get the clip-ons and saddle dialed in as best I could, didn't change anything else (used my 60mm wheels from the TT bike).