Charmin Ultra Strong Clean Touch Toilet Paper, 18 Family Mega Rolls = 90 Regular Rolls

Q: How many sq feet per roll? That's the only way to comparison shop.

37.125 sq. ft. per roll. As it currently ships (November of 2020), it comes in three separate packages of 8 rolls each. Each pack of 8 rolls has 297 square feet of toilet paper. Three times 297 = 891 total sq. ft. for 24 rolls. 891 sq. ft. divided by 24 rolls = 37.125 sq. ft. per roll.

Q: If i have this item in my subscribe & save, will i receive it (covid-19 outbreak)?

If the product shows "Currently Unavailable" (Which it does now), it's unlikely that you'll get it this month unless Amazon receives stock, and doesn't sell out again, between now and when they need to ship to fulfill your order. I don't think they keep a separate inventory for subscribe and save. It's happened to me before for some stuff that I've ordered - they just don't charge you for it this month and it'll get sent out next month, if it's in stock.