I believe the CMV. ship Astoria sails from Poole in the spring and autumn seasons. Worth a look?
I have researched a little more and would add this to my previous recommendation.
Sailing from Dover on the 19th May to the Fjords is Saga’s new ship Spirit of Discovery. I recently cruised on this ship and it is one that you may enjoy. It is fully inclusive including speciality restaurants, excellent service and ambiance plus all cabins are well equipped with balconies.
Certainly Fred. Olsen and Saga appear to fit all your criteria.
There are other cruise lines but they do not fit into the criteria you have given.
Please let us know how you get on.
You might like to look at Hurtigruten. They have smallish ships and you can pick them up at Bergen. You can do the round trip or make your own way back from Kirkenes.
They are starting cruises from Dover so this may help:
Have a look at Fred. Olsen. All their ships are covering the Norwegian Fjords in May. They are smaller ships and from personal experience offer excellent food and service. I have sailed on them with my wife and as a solo and never been disappointed.
Im looking for any recommendations for a norwegian no fly cruise. My other half wont fly and we are thinking of doing Norway in May or June but dont want to go on one of those large impersonal cruise ships. Im looking for something small and more personal and a bit more upmarket. Grateful for any recommendations. Ive checked the big companies and they arent really what Im looking for.