If you buy a second modem, by all means set it up to save moving things. But, and this has been emphasised before, only have one plugged in at a time. The exchange will see two modems as a fault and disable the ADSL.
OnePlus 5T review: Hands-on
Illustrator Andrés Lozano on his improv line work, brazen use of colours & hand sketching
iPhone X review
Comment envoyer gratuitement des gros fichiers ?