M. divisella has a bit of a history of wintering in the garage:
2018 - a total of 22 released between 2nd April and 25th April (max. nine on 2nd April).
2019 - a total of 30 released between 27th February and 8th April (max. six on 20th March).
Also in 2019 a total of nine were found active in the garage or house between 20th September and 21st December.
I have only ever had one individual come to light; on 22nd April 2019.
Where they come from and why my garage is a favoured hibernation site I don't know. There is willowherb in the garden but I have never found any larval feeding signs etc.