The lake I live near although has several Phragmites beds they are not extensive and lots of the shoreline is bare, Bitterns are resident. February is quite early but not unknown.

They are by nature shy and maybe only venture out in quiet remote areas, as were those I've seen or heard about, one large reservoir where I used to see them in winter had very few reed beds those that existed were mostly Phalaris although there was a small patch of Phragmites

They are partial migrants so it's possible any Bittern may travel around, they all will use fairly open areas especially in winter when away from breeding areas.
Grey Herons ,Storks and Little Egrets can also be found in open areas in damp fields, the latter sometimes mistaken for Cattle Egrets

Well I have so get out more. They also like damp areas close to lakes with open ground and patches of rushes particularly when hunting frogs, not just me but a local farmer reported one, he thought it was a chicken at first, it was at least 50 metres from the lake

Bittern are not found exclusively in reed beds, but I actually live near a lake in an area noted for Bitterns, this is not the first I've seen from my house, either flying or in one instance taking worms in a damp area of a field where cattle had been standing.

There are two of us, Richard and me, they are difficult to spot, Richard wants to go again to-morrow afternoon, we think at least two had fledged and with the one we saw leave possibly 3.

Seen a couple of Commas, also Wall and Grayling and few Painted Ladies, hoping maybe Clouded Yellow not seen any for a few years, Seen a couple of Humming Bird Hawks and a friend also had one in her garden.

Probably, depends on the weather, sometimes do sunset/sunrise.

Good year for Speckled Wood, Gate Keeper and Red Admiral , Lots of Orange Tips earlier and at last a few Peacocks