65k and undisclosed climbing but given Vet times range from 3hrs to 6hrs it’s likely to be around 1500-1800m?
Lets say you are aiming for a 3.5hr time which would have you top 10 or thereabouts in Vets.
You’re likely to have climbing efforts of 5-10minutes followed by recovery and some steady state.
Your training is probably about right it’ll be a question of how long you can keep on putting in threshold efforts.
I think the single biggest thing you can do is work on your pacing over 3hrs. Were it me I’d train as per normal, reduce a bit on the 29th, 30th and 31st and put in a hard 3hr ride on the 31st to work out how hard you can go and still make the distance without cooking.
As you have a history of overtraining prior to events I’d watch what you do the week after. Much Reduced length but intense intervals and some Z2.