If they are just getting to the ropey look, but not showing other problems, I'd just regenerate with a fresh set of clones, and flower the moms in 5, 0r even 10 gallon pots if you can find any.
This is what I do. Whenever I do a run of clones, I take extras, so that I can keep the most vigorous cuttings and turn them into new mothers who can in turn donate cuttings within the month, and I train them out to give a short, wide canopy that exposes the most nodes to light (=lots of cuttings in a short time).
Personally I don't keep moms past the point where they are too big to flower in a 3-5 gallon container. I prefer moms to live in a quart container, or for a strain I run a LOT of, a gallon pot.
The reason behind this is that first off, were I ever to need to get the fuck outta Dodge, I could cram the bitches into a rubbermaid tote, toss them in the trunk, an get them to safety. Losing genetics is tragic. I have had to do this before. You CAN'T do it with a big mother for obvious reasons!
Second, I'm running too many strains to keep huge moms. They each get about a square foot of floor space, lol, and have to deal with it!
Third, prepping a smaller mother for cuttings is EASY!!! The cycle is: Feed with grow fert (high N) until vigorous new shoots are observed. Switch to a bloom fert+ superthrive to load up on P and thiamine for rooting (one week before taking cuts). Take cuts. FLUSH. REpeat.
The flushing step is a bitch if your moms are in giant homes.