I know I should not say this on this forum that is sponsored by Thorn, but there are a lot of nice bikes by other brands that would work great for long day rides or an overnighter where you sleep indoors and do not need camping gear.  I am not going to suggest any brands, I am in USA where the brands and models vary greatly from the choices in the UK.

I own two Thorns, but if I was going to sleep overnight somewhere where all I needed was a change of clothing, toiletries, and potentially some rain gear, my choice would be either my road bike or my randonneuring bike.  For that, a Carradice saddle bag, along with my handlebar bag would work great.  The rando bike has fenders, 32mm tires, and wider gearing than my road bike with 28mm tires, so the anticipated road and weather conditions would drive my decision on which bike.

Ian,

I've been very happy with my Mercury.  I've  done a number of short tours since I bought it in the spring of 2022 - overnights, and a weeklong tour over mixed terrain.

One consideration for me, which I didn't expect:  My Mercury came with a Ryde Rival rear rim, and a disc brake.  No problem with the disc, but the rim posed a big problem for changing tires -- my arthritic thumbs limit the tires I'm able to mount and remove.  If I'd known in 2022 what I now know, I'd have ordered rim brakes at the rear and a rim better suited to clincher tires.

I tried mounting Panaracer Gravelkings (650B x 48 mm) in late 2024, and it was just doable on the rear rim -- by that time, I'd changed the Ryde Rival to a DT Swiss 540G, recommended by Thorn. (No trouble mounting or removing those at the front -- that rim is a Thorn alloy rim.)  They were lovely tires, BUT in August this year, about to start an overnight, my TPU tube on the rear expired after just 500 kms. I was able to change the tube only with the help of my riding mate.  I realized then that I wouldn't be able to make a roadside repair by myself if I had to -- and that I might not be able to do so in my home workshop, either.

Now, I've shelved the Panaracers, and have my Marathon Supreme back on the front. At the rear, I've switched out the Supreme -- my thumbs prevented me from mounting it, even with the help of the Koolstop Tire Bead jack.    What I have instead is what I was able to mount, despite my thumbs:  On the advice of Andrew, the very experienced owner of my LBS, I now have a Marathon Plus beaded tire on the rear wheel. ("Shocked and appalled!!" readers will say.  I was a bit hesitant, to be sure, but Practical Reality intervened.) Both F & R tires are 650B x 40 mm, 38mm actual inflated.  My Mercury now weighs a couple of hundred grams more than it did with Supremes fore and aft, but on an admittedly short 90-minute ride along the river and into the hills, I couldn't tell difference.

Take this FWIW,

Cheers,  John

A later PS:  Happy to share with you the specifics of my approach to loading the bike, if that's useful.  It's not the usual rearward pattern.

I have a good Raven fork that might do the job, can you send me a PM?  It is the twin bridge type
Also a Ridgeback Expedition fork for disc brake.
Andy

DM sent

Thanks, Adrian.  I do remember going along the B3157 in a rental car and descending the Abbotsbury Hill, and thinking..."Jeez, climbing this'd be a handful on a bike."

Lovely countryside -- I get all weepy & sentimental seeing the Google photos...

Enjoy, in any case!