Dave, I was thinking about you today. Well done mate.
If you have more to do like this one, you could use Viscoline or other plastic sheeting, stick this together with gaffer tape and make a kind of pool liner leading out through the door. You could use ladders laid flat to keep the edges up higher.
How far in from the glass was the floor getting wet?
You could with care do most inside work with plastic sheet and tape. Dai