Condolences on your recent bereavement.
As has been said it's very early days and as much as you want to move on this move may be too soon for you.
Also you have mentioned your concerns re mice and a shared entrance.
These are your concerns and they are there for a reason.
Your concerns have already lead you to ask questions on here and have given you time to stop and consider your choices.
Both are very good things and as Nonogran has already said "what is your gut telling you ?"
It's good that you are thinking hard about this move and not just working from your feelings.
I understand from reading your post that you would normally discus these things with your husband but it seems to me that you already have a reasonable handle on this move and any future issues.
May be this isn't the time or the property swap for you, only you can make the decision on your future, take the time you need.
As for shared entrances, my sister lives in a flat with a shared entrance, it's not a major issue for her at the moment but what she has had to deal with is some very difficult neighbours.
When she moved it the neighbours were lovely, friendly, respectful and followed the rules of the property, no problems.
Over the years she's had bikes, motor bikes, furniture and rubbish in the shared entrance to navigate getting in and out so I think you are wise taking your time to think this through.
Can't comment on the nice but if there is a problem where you are doing your research is a good thing. Best of Luck with whatever you choose to do going forward.