Considering the Iceland volcano, I'm suggesting you avoid Europe and Britain. That volcano is likely to be unpredictable for a while.
If the southern hemisphere is too expensive (pity - if not Australia, then NZ would be a very romantic place to come to) then I have two suggestions -
1) Stay 'home' and find a US-based resort and head there. Pick somewhere that has a lot of fun (just for two) activities. For example (an Aussie example) - difficult child 1 & daughter in law went to Bright, a lovely alpine place in Victoria, Australia. There they could visit farms, go on a local food trail tour (just them in their car and a picnic hamper) buying cheese at the cheese factory; fresh bread from a country baker; fresh fruit and vegetables form a roadside farm stall; rainbow trout they fished themselves from a local trout farm. They have a hedge maze there, a huge one. Lots of rambling walks through some magnificent countryside. For them, it was a magic time.
Another example - easy child 2/difficult child 2 & SIL2 went to a resort at the Gold Coast. Again, lots to do locally. They went to a lot of theme parks because that is what they wanted to do. SIL2 went to the beach a few times (I think).
OR
2) Go on a driving holiday and simply go wherever you feel the mood takes you. Let it be an adventure. Have a rough itinerary planned but don't book anything in advance. Let it be an adventure.
We found in NZ, there are some wonderful B & B.s We've also found wonderful B & Bs in Australia, often you don't hear about them but only see them as you're driving past.
The B&B we found in NZ - it was so funny! We'd arrived in Christchurch mid afternoon and needed to find somewhere to stay. We saw a sign for a motel that had been given a lot of local tourism awards for hospitality, so we booked in there. It was OK, but nothing special. It looked pretty, the people were very friendly; but it was COLD! It was off-season, midwinter, and so they only turned on the (off-peak) heating when we arrived. And it wouldn't kick in until 4 am! But once the heating kicked in, it was supposed to heat this big concrete block which would warm the little box that was our rooms.
Next day we'd book tickets on the train to travel across NZ and back, over the (snow-covered) Alps. We got back to the motel room, anticipating the warmth from the concrete block at last - to find the motel owners, worrying about condensation, had cleaned the room (as they do) and left the windows open deliberately, to ensure plenty of air circulation. COLD air. Another cold night. husband & I huddled under the blankets with an accommodation guide I'd filched form the motel office and plotted.
I found a farmstay B&B in the book, just out of the town. I rang them to find out if they had space for us and they did. husband was sceptical. We were driving along trying to find the place, or ANY place for our last night in NZ, and husband said, "I think you have a glorified notion of what a farmstay will be like. You do realise that farms have manure, smells, and mud?"
Just then we rounded one of those magnificent hedges they have in the Christchurch region (strong winds there) and there was the place - a fabulous Tudor-looking mansion. Glorious. Huntingdon Grange (look it up). Both our jaws dropped.
OK, it was cold. But the owner brought round several powerful heaters to warm us up. We had a lovely stone cottage just for us, it looked onto a dressage ring where their daughter was practising for a competition next day. The main house (the manor house) had a large drawing room (can't call it anything else) with a wall of books I enjoyed reading, in front of the roaring log fire while the owner brought me coffee.
Breakfast was marvellous - five star. All included in the fee, of course. And the cost for us to stay there was STILL less than the cold little motel box in the heart of the city, we'd stayed in the previous two nights. We cursed ourselves roundly, for only finding this place on the last night. If we ever go back to NZ, we're staying there again.
difficult child 3 took their dog for a walk (we asked if he could) and we also went for a walk into the paddocks to feed the sheep and alpacas.
I've looked around - it's worth looking into B&Bs, they can be cheaper. They generally are much more pleasant than a motel room.
We have B&Bs in our village, easy child 2/difficult child 2 used to work for one (cleaning rooms and detailing them to a very high standard). The owners can give you space, or welcome you like family. It depends on you to a large extent, on what you want. There are often books published by local motiring associations that review B&Bs and help you find good ones. Try seeing what you can find.
Marg