I assume by ‘land rover-ing’ you mean travelling the hike by way of an off road vehicle? Putting aside the argument for allowing off road vehicles onto the green roads and tracks normally only frequented by farmers, horses, cycles, off road motorcycles and walkers (colours to the mast - I’m very much against access to these delicate tracks by ANY powered vehicle) you’ll find that the better hikes in the north are inaccessible to motorised vehicles and indeed in many cases protected against them by barring the way. Even if you could gain access for a Land Rover or similar it would be dangerous and hugely uncomfortable I imagine.
There are off road vehicle drives available in the Lakes - at a price I should imagine! - but the better, more interesting (to my mind) places are only accessible on foot, thank goodness. I’m afraid there’s no point in hoping for enlightenment on walking if your other half believes all walking to be a trudge. It’s like jazz - if you have to ask you’ll never get it!
Hope you can get something arranged that suits you both. Being prepared to travel by Shanks’s Pony means you’ll have more than enough to go at!
EDIT: I’ve had a quick look at the Yorkshire Vehicle Hire site and reading between the lines there (and the reviews) there doesn’t seem to be a lot of off-roading involved. In fact some the the roads shown on the site I recognise and have driven in my own decidedly non off-road car! So I think maybe these are just an alternative to a camper van. YVH are based at Great Ayton (maybe a little tricky to get to without your own transport - but not impossible - I would think) under the North York’s Moors, which are a favourite of mine, but to a visitor with limited time, especially wanting to hike, I’d concentrate my attention on the limestone country of the Yorkshire Dales, I.e., the ‘Three Peaks’ area. Alfred Wainwright’s ‘Walks in Limestone Country’ though old (but relatively recently updated by the equally eccentric Chris Jesty) is the bible for this area, full of interesting day hikes of varying length). Your own transport to navigate this fairly large area would be compulsory as public transport is sparse to non existent (much of the area is remote from major habitation).
The Lake District is a completely different kettle of fish with better public transport links - it kind of depends where, if anywhere, you base yourself. It’s largely off-road driving unfriendly, but the off road (day?) trips I’ve noted appear to be based around the Windermere area. Hiking there? Well I’ve been at it over fifty years and still have more to do!
Hope this helps.