The second Ashes Test match is at Lord's (St Johns Wood in north-west London) from 28 June to 2 July 2023.
The fifth and final match of the series is at the Oval (south London) from 27 to 31 July 2023.
It's hard to know which one to pick. It might depend on whether it's easier for your husband to travel to NW London or to S London.
If you pick the Lord's Test, that would obviously be early in the series when there will still be everything for both sides to play for.
If you pick the Oval Test, it might be EITHER that by then each side has won 2 games, so this is the exciting decider Test between them - OR it might mean that one side has won everything so far, so that this final fixture is a dead rubber which no one really cares about.
If I were you (assuming your DH can easily travel to the ground), I'd go for the second Test - the one at Lord's, when everything in the series is still to play for.
Either way, I would book tickets for one of the first three days to be (reasonably) sure of seeing a full day's play. Test matches are supposed to last five days, but I think in recent years many of them have ended partway through the fourth day.
Other posters may well have better ideas than me!
Wish you well, OP 