I'd suggest you at least do some shorter trips at first. Plenty of the UK to see!
As a non driver, believe me, it is not boring "staring out of a car window" in fact, you get the best part of the deal as you can see the passing scenery , places of interest that you might go past - all without the stress of having to make sure you are on the right road, avoid traffic etc that is all involved in driving any distance.
Not much luggage space? no problem! Most people take too much anyway. All you need is a couple of changes of clothing that you can roll up in your bag/ case plus extra changes of undies and toiletries, not forgetting a good sunscreen and sunglasses. Doesn't matter if you have to wear an outfit more than once - no one will be seeing you for more than that anyway and you can buy clothing that can be washed in the sink if needed and will dry overnight.
It's also surprising what you can squeeze into nooks and crannies around a car if needed!
Oh, just make sure that the distance you plan to travel each day is sensible - no point in going for 100+ miles and not enjoying the trip because you are both too exhausted - it's not a race and you can always re visit the bits you don't reach!
Static caravan purchase is it worth buying