Vera, we've got 'em too, just not as extreme as yours but still record breakers for us on this side. Problem is, things that are not evergreen have been breaking dormancy and it's an especially vulnerable time for some. I've wheeled plant carts with young plants, cuttings into the carport the last two nights. Tuesday night I got worried about a flat of meconopsis, others, that are about two breaths away from germinating, afraid a hard freeze might kill those, went out in my pj's at midnight and put them into the back of my Explorer. It's new, how's that for a cold frame :) I've been covering in the ground (sheets, tablecloths) a styrax native to california and only hardy to barely 8b, melianthus, and fritillaria - and for the first time ever, my hydrangeas that have big fat buds popping out all over. I don't have the material to adequately protect my 6' hardy fuchsias. This can quit any time now :( These temps weren't so hard on them in Dec but March concerns me.

So it’s been almost a decade since this post was active, but i have the same question as the original post, except i live in zone 4 (-20 to -30). Sorry in advance for a long post. I’ve been growing roses for 4 years (135+ in the ground and 10 in pots lol, since i forcibly retired). But every early Winter has been different. Like tonight we’re getting our first snow but the lows are going from low 40’s down over 4 days to 24,14,then 9 and 8, then next week it’s back up in the 60’s high/40’s low. My general rule of thumb is 3 nights at 25 or less (not lower than 15) then in the garage til Spring (May 15 is our last frost). Haha - but Mother Nature hasn’t cooperated the last few few years, as noted above (Sudden dive down to single digits after being 23 to 45). Last year i watered them with warm water before i went to bed down to 13, put them in the garage if lower than that. If the leaves still had green and weren’t crunchy, would leave the garage door up in the day (faces NW) if over 35. Overall worked, except 5 newly planted pots (Kashmir) in July were dead in the garage in May, before the last frost. My wife won’t let me put quilts around them outside, despite us never using them ( my granny in Gatlinburg made over 20 quilts just for me over the years, so we have plenty🤦🏽). And yes, for the TN’ers, Johnson City in the 1990’s was way colder and snowier than Knoxville/Maryville/Athens where i grew up in the 70’s. Montana is quite a bit worse haha as you can imagine, but worth it. Though last year in December, it went from 60 down to -30° for a week. Unusual, but that’s Montana. One Winter it never got below -5. And Billings (where I live) is way warmer than Bozeman (zone 3), so I should be grateful. Any suggestions when i should put the bigger pots (Pope John Paul, Munstead Wood, New Dawn, Plum Perfect) in permanently? Some pots are 16” w x 33’, most are 32” w x 25”. And the few Emily Carrs i started late Summer are only in 12” x 8”. The latter will go in after 25°. Help me pick options for the bigger ones: (most likely) i’m probably going to do the trolley shuffle back and forth at least from the South deck (somewhat exposed) to the pavement up against the NW driveway (although the big pots weigh 50lbs or more DRY lol, so my back would prefer not to lift and put them on the trolley unless permanently going in the garage for the Winter). I could leave them on our South facing deck which is full sun and elevated, and against glass walls, but it would likely still be single digits up there. put everything in the garage if below 15°, then back out if higher. warm water them at bedtime and put in the NW driveway. warm water but put them on shady NW ground. put them on a full shade North concrete floor patio/brickwall alcove with warm water for single digits, and leave them until consistently below 25, with the shade hopefully getting them dormant quicker, although the garage may still warm up to 50 in a few weeks. Sorry for all the options, but you guys sound as obsessed as I am about my babies haha. (Wife thinks i’m crazy, but the roses at least keep me out of the house and away from her for part of the day lol, again, now that I’m retired). And the neighbors go ape over all the flowers, so it’s fun. Thanks for reading this long post, and for any suggestions on what you’d do.☺️🌹

If I understand correctly, the beardeds will eventually have to be moved to a sunny location? And it's this winter's rain you're concerned about? Since it has great drainage, they may be ok. Unless you dig and pot them for the remainder of the winter, the tarp seems like a good way to divert rain. I would check them regularly and if a rhizome is soft, lift it, wash off the dirt and let it dry overnight. Then perform 'surgery' if it has rot.

This is our "Blackberry winter" Happens every year, about, at this time. Remember I said earlier that we wouldnt be safe until May 10-12? However, I believe we've made it this year. Sure hope so, cause I cant move anything.