Welcome to A4A Vincent.
Nice video, thank you and good luck. Just a comment. Both peas and lettuce can take a little bit of frost and will be fine in a cold poly or greenhouse now. No need to mollycoddle unless we get something like -8C. But any tomato or pepper seedlings, or cucumber etc need all the light and warmth they can get. Hope the slugs won't get all your lettuces again.
I planted lettuces in the greenhouse late last autumn and they survived winter in the cold greenhouse ok and they are now really putting on some growth. Nice salads with lettuce, celery, lamb's lettuce and cress and there will be lots more before the space is needed for the tomatoes.