70 puzzles ?.. WOW!!
I used to enjoy doing puzzles many years ago despite having little patience ... only like Ravenscroft tho'... and never more than 500 pieces..I would just do it on a board, and slide it under the sofa until I had the patience to return to it..
Sad story alert..
The first time I ever did a 1000 piece puzzle.. I was still living at home.. aged about 19 or so..
I did it in the dining room.. wasn't permitted to do it on the dining table, so I took an old large suitcase and did it on that.. sliding it behind the sofa each night ..ready for next time
It was a particualrly difficult one Oval ...all flowers ...
I'd do it for an hour each night after I got home from work...
It took me several weeks to do.. and I had just a few really difficult pieces to find .. when I came home from work one night, to find my father had taken the whole puzzle and broken it up.. just out of spite..

.. no other reason, but that he could!!
I never did another jigsaw there again..