@Helen0
I had a similar situation with a local, long-term guest who was temporarily homeless. She contacted me prior to the restrictions but didn't book, hoping that her situation would soon be resolved. However, due to lockdown, it wasn't and, by the time she contacted me again, my calendar had been blocked.
Now, I checked the Government's website and this guest did indeed fall into the exceptions under which we CAN offer them accommodations. However, even though the CS rep I spoke to agreed with me, she was unable to lift the block on my calendar. It was not a great situation as this guest seemed to be in genuine distress. Can you imagine being in that situation right now? It's not like you can just go crash on a friend's sofa!
In answer to @Suzanne302 's question, it's a tricky one. At the moment, UK calendars are blocked until 9th May, which is not that long away, but I suspect this will be extended as it has been a few times already. I don't think we are anywhere near being ready to host travellers. So, for me, right now it's less about when but about whom I host. I was already focusing on long-term stays well before this crisis and will continue to do so, keeping my long minimum stay requirements, but will focus on local guests, like the one above, if they come along.
You still have to be very careful though as guests are sometimes not totally transparent about their situation. I had one request from someone who told me he had been in quarantine for three weeks in the UK. This turned out not to be the case. He had been in lockdown like the rest of us, not quarantine, and only for nine days, prior to which he had been travelling abroad.
I think you have to decide on the type of guest you will be comfortable hosting and ask a lot of questions before accepting a booking. It is too soon to return to 'business as usual'.