Bed suitable for older cavaliers?

We have 2 cavaliers who are starting to get a bit older now Sally is almost 10yrs and Lois 8yrs. They are generally in very good health so far. They both have heart murmurs but currently asymptomatic. They just sleep in a oval type plastic bed with a cushion filling at the moment it's quite roomy. I'm worried that it's not really suitable as they're getting older and as it's on a tiled floor it could feel a bit cold? What beds do others have for their older Cavaliers and one that is washable and will keep them cosy and warm?

When our ShihTzu reached a certain age, I slipped a pet bedwarmer into his bed and he seemed to like it. We left it plugged in all the time, during the colder months, and never had a problem with it.

The one we used is on amazon's USA site, and I also found it in the UK in case you live there:
UK amazon --- https://www.amazon.co.uk/Manufacturing-Warmer-Large-11-Inch-23-5-Inch/dp/B001AZLVG6/ref=sr_1_1?ie=UTF8&qid=1474991629&sr=8-1&keywords=K%26H+Manufacturing+Pet+Bed+Warmer

USA amazon --- https://www.amazon.co.uk/Manufacturing-Warmer-Large-11-Inch-23-5-Inch/dp/B001AZLVG6/ref=sr_1_1?ie=UTF8&qid=1474991629&sr=8-1&keywords=K%26H+Manufacturing+Pet+Bed+Warmer

My dogs love this bed. I have the extra large size and all the three pile in it together. It is reversible and washable. I have had it for years. My dogs are 14, 13 and 9 years old. I think they like it because they don't have to step over any barrier to get in. It's not cheap, but it's been well worth the price. The amazon site is from the US but you could probably find it on the UK amazon site also.
https://www.amazon.com/s/ref=nb_sb_...ger+&rh=i:aps,k:bowser+reversible+dog+lounger+

I splurged for Sparky as he got older. He likes sleeping on my memory foam bed at night so he got his own for during the day (when he doesn't have access to the bedroom)

http://www.orvis.com/p/faux-fur-ult...MNiYqdnZBoA3p_bK70Od8uThq455dfmJKAaAgbU8P8HAQ