Not long term no, despite having a great relationship with my parents and with dh's mum.
MIL moved in with us for 3-4 months during the first lockdown. FIL was very ill and died in the first couple of weeks of that lockdown, and was in hospital when it started. We couldn't see MiL left at home, in isolation and lockdown, so she moved in with us.
Whilst it was fine, our home didn't feel 'right' - I don't think anyone was fully relaxed, partially due to the circumstances but also because our home didn't feel like our own for a while, and equally for MiL she must have felt less relaxed as she wasn't at home.
After lockdown and when she finally went back home, a gradual process, I think we all felt much better. She was back home and able to see all of our friends, and out home was back to being our own again.
It didn't really affect mine and dh's relationship - so much other stuff was going off at that time anyway, so nothing was particularly great for any of us. But it didn't make it worse.
We did what needed to be done at the time. However, we all know that we could never have done it long term, for all of our sakes.