Wow 6 months is a long time to have anyone staying in your home. It's good you intend keeping up with your hobbies but, like you, I would want some down time at home to clock off and would need to retire to my bedroom from time to time to read a book, phone a friend ext. I'm not really keen on a TV in our bedroom, but in these circumstances I would be heading to the shops pronto to get one installed if you don't have one. That way you can always go off and take a break. I wonder if it would be possible to set up a routine of 'me' time right from the start. For example saying grannie (if that's what you are called) always goes up for a rest if I am home between 2.00 and 4.00. That way you are not waiting until things get on top of you and ending up stressed and maybe saying something sharp on the spur of the moment.
You sound lovely, being willing to do this for your DH. I love my daughter and it's great when she is around but I think that length of visit, whoever is coming would be hard. I would carve out some established time for yourself right from the start. Hope it goes well. 