Sorry to hear that Stu...
Firstly, disclaimer, I'm similar to JohnClimber in terms of understanding but...
Happened to me coming out of Chesterfield after some floods in 2017 I think. I hadn't realised but the shortcut I had taken was actually the same distance as the direct route to the motorway but bloomin satnav and 'engage brain etc etc' wasn't worming for me. Anyway, it was down in the valley or whatnot and around a bend... Seen another car parked up just before it but 'engage brain' didnt qyite work for me and once I was in I frantically hoped I'd make it through. The car was an LPG conversion by a shitty (its not a swear and he was very very shitty) so-called mechanic*
Anyway, I was still in the first year from the lpg conversion (from the shitty place who had reqyested that I went and topped up on lpg first time I went to collect post conversion so he could tune it... the shitty mechanic.. or did I already say that) and had just started making back my investment. Some kind souls with tractors (working on some building site up the road and maybe responsible for the poor drainage in first place

) pulled out the car and left me on the hill kindly...
As I waited for my younger sibling to come recovery me it suddenly started working again and I managed to get a good months more worth of driving out of her (estate Honda Accord Type S 2.4 L... made for economical folk apparently as I could never get any decent throttlw respinse out of her and thwse engines were the talk of the forum for being sluggish) before she/he/it/whatever broke down on motorway. Didnt quite break down but started making some massive clunking noises from engine bay and I managed to get to the next sliproad and stopped on side.
An hour and £100 or so later on urgent AA (or RAC or GF) membership I was happily being towed to my fav garage in Huddersfield. A few smirks later (he knows I only turn up at his when I've exhuasted my own cheapskate avenues) and he advised that it sounds like bent valves and best move it on. Sold on fleabay as Spares/repairs and exported to Romania or summat (DU05HXD was the reg I fodnly remember) for the handsome auction of £700ish...
Anyway, every .... has a silver lining. I've been thinking about starting a 'flood near you and its here' thread after having waded (I turned back... it was dark... did get as far as the submerged car before it reached my waiste.. hood call on taking the bike as it didn't suffer too much) to my waiste on Monday. I guess this will finally help me get it started
Erm... final thoughts.. I know you won't but, maybe it might be more efficient letting it go
*The flooding nor the broken car was probably not his fault but having seen so many broken 'LPG ' cars outside his place should've alerted me.. Besides, as soon as he'd done the job the EML came on and he never owned up!! Did I say he was sub standard(ty)...

NB. Thats what my 'waded flood' looked like in the light a few days later. Submerged car not to be seen which makes me think I obviously went in pretty deep before seeing sense